Computed Tomography Volumetric Analysis of Frontal Sinus Pneumatization and its Effect on Lateral Lamella Angle

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This study aims to investigate the relationship between frontal sinus volume and lateral lamella angle. Methods 150 computed tomography scans of paranasal sinuses (300 sides) were retrospectively reviewed. Pneumatization patterns were classified according to volume using a three-dimensional reconstruction analysis of the frontal sinuses. The angle formed between the lateral lamella and the horizontal plane in continuation with the cribriform plate was measured and grouped according to Gera classification based on the hypothetical risk of iatrogenic injury. Analysis of these measurements was conducted. Results A positive correlation was found between frontal sinus volume and lateral lamella angle. Hyperplastic frontal sinuses were the most prevalent followed by middle-sized sinuses. 5% of the frontal sinuses were aplastic. Lateral lamella angles ranging from 45 to 80 degrees (Gera class II) were the most common. Aplastic and hypoplastic frontal sinuses were common in subjects with less than 45 degrees lateral lamella angles (Gera class III). Males had significantly higher frontal sinus volumes and lateral lamella angles than females, while the influence of age was insignificant. Lateral lamella angles were significantly higher on the left side. Conclusion The frontal sinus volume affects the lateral lamella angle. Larger frontal sinuses are associated with higher lateral lamella angles and vice versa. Understanding this anatomical relationship can help prevent surgical complications. Frontal sinus Lateral lamella Computed tomography Volumetry Endoscopic sinus surgery Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Endoscopic sinus surgery is an effective treatment for paranasal sinus diseases. Although the procedure is minimally invasive, there are risks of cerebrospinal fluid leaks, orbital, intracranial and vascular injuries. In most cases, major complications occur due to variations in the skull base and paranasal sinus anatomy [ 19 , 20 , 25 ]. Preoperative computed tomography is essential in assessing the risk of these variations. Frontal sinuses are surgically important for many reasons, including their proximity to the skull base and orbits, their complex and variable morphology, and the effect of their pneumatization on neighboring structures. Frontal sinus pneumatization patterns have been classified based on two- and three-dimensional views [ 9 , 26 – 28 ]. Volumetric measurements can be obtained through three-dimensional reconstruction analysis, which allows for more accurate categorization of pneumatization patterns [ 11 , 21 , 28 ]. The anterior skull base is composed of the cribriform plate and fovea ethmoidalis; these two parts are connected via the sloping lateral lamella of the cribriform plate, which is the most delicate and vulnerable part of the skull base [ 14 ]. Several studies have linked certain anatomical variations, such as a steep or low-lying anterior skull base, to a higher risk of surgical complications [ 8 , 14 , 15 , 19 , 20 , 22 , 25 ]. The effect of frontal sinus pneumatization on the height of the cribriform plate has been investigated in the past [ 2 , 4 , 6 , 10 ]. However, determining iatrogenic injury risk based solely on the height of the skull base is not sufficient without considering its sloped configuration. This is the first study investigating the effect of frontal sinus volume on the lateral lamella angle. Additionally, we aimed to examine the differences in frontal sinus volume and lateral lamella angle according to gender, age, and side variations. Materials and methods Subjects and computed tomography imaging This retrospective study included 150 computed tomography scans of paranasal sinuses (300 sides) retrieved from the Picture Archiving and Communication System (PACS) of the radiology department at King Salman bin Abdulaziz Medical City in Medina, Saudi Arabia. The Local Institutional Human Ethics Committee reviewed and approved the study protocol. Images were acquired using Aquilion Prime SP CT scan system from Canon Medical Systems®; a dual-energy CT scanner with radiation tubes that can complete a full rotation in 0.35 seconds and scan up to four centimeters of anatomy per one tube rotation in a range of 80 to 135 kVp. A pre-equipped scanning protocol was used. An average of 60 two-mm slices were obtained per scan. The axial, coronal, and sagittal planes were automatically reconstructed into 0.5 mm soft tissue and bone window slices. Radiation factors were defined and controlled automatically by the automatic exposure control (AEC). To ensure the accuracy of all acquired measurements, we excluded subjects under 19 years of age. We also excluded inflamed sinuses, sinonasal tumors and polyposis, previous surgery or trauma, congenital craniofacial skeletal abnormalities, skull base pathology or defects, and scans with inadequate technical quality. Data processing and radiological measurements Data processing was implemented using ITK-SNAP software ( www.itksnap.org ), version 3.8.0, which is an open-source tool capable of segmenting images, analyzing data, and creating 3D shapes [ 29 ]. The processing begins by contouring both right and left frontal sinuses using the active contour tool, which can create a region of interest defined by the user on axial, coronal, and sagittal planes to trigger automatic segmentation for each frontal sinus separately. Then, volume (mm 3 ), voxel count, and intensity mean were obtained automatically using the volume and statistics tool (Fig. 1 ). Based on volumetric cutoff values suggested by Aslier et al., the frontal sinus pneumatization patterns were categorized into four groups: aplastic (no pneumatization), hypoplastic (less than 1131.25 mm 3 ), middle-sized (1131.25 mm 3 to 3328.50 mm 3 ) and hyperplastic (more than 3328.50 mm 3 ) [ 28 ]. The angle formed between the lateral lamella of the cribriform plate and the horizontal plane in continuation with the cribriform plate was measured in coronal view (Fig. 2 ). According to Gera classification, the angles were divided into three classes based on the hypothetical risk of iatrogenic injury: Class I (more than 80 degrees, low risk), Class II (45 to 80 degrees, medium risk), and Class III (less than 45 degrees, high risk) [ 8 ]. Statistical analysis The statistical analysis was performed using SPSS version 29.0. Descriptive statistics were utilized to analyze patient demographics, lateral lamella angle, and frontal sinus volume. The Mann-Whitney U test was used to compare frontal sinus volume and lateral lamella angle between genders. Non-parametric correlation analysis, using Spearman rank-order, was applied to examine the relationship between frontal sinus volume and lateral lamella angle. Statistical significance was set at P < 0.05. Results A total of 150 computed tomography scans of paranasal sinuses (300 sides) were analyzed, ranging in age from 19 to 73 years, with a mean age of 35 ± 12 years. Of the subjects included, 53.3% were males and 46.7% were females. Most of the frontal sinuses were hyperplastic, accounting for 45%. Middle-sized frontal sinuses (36.7%) were also common. Aplasia was observed in 5% of the examined frontal sinuses. In most subjects (72.3%), lateral lamella angles ranged from 45 to 80 degrees (Gera Class II). 4.7% of subjects had lateral lamella angles less than 45 degrees (Gera class III) (Table 1 ). Table 1 The distribution of frontal sinus pneumatization patterns and Gera classes of lateral lamella angles Total n (%) Right side n (%) Left side n (%) Frontal sinus pneumatization pattern Aplastic 15 (5%) 8 (5.3%) 7 (4.7%) Hypoplastic 40 (13.3%) 22 (14.7%) 18 (12%) Middle-sized 110 (36.7%) 59 (39.3%) 51 (34%) Hyperplastic 135 (45%) 61 (40.7%) 74 (49.3%) Lateral lamella angle Class I 69 (23%) 43 (28.7%) 26 (17.3%) Class II 217 (72.3%) 103 (68.7%) 114 (76%) Class III 14 (4.7%) 4 (2.7%) 10 (6.7%) The mean frontal sinus volume was 3,254.8 ± 2,521.8 mm 3 and 3,807.6 ± 2,892.8 mm 3 on the right and left sides respectively; however, this difference did not reach statistical significance. The mean angle measured at the lateral lamella and the horizontal plane in continuation with the cribriform plate was 65.8 ± 12 on the right side and 70.2 ± 10.9 on the left side. The angle was significantly higher on the left side (P-value = 0.001). The analysis showed no statistically significant differences in frontal sinus volume and lateral lamella angle according to age. Gender differences in frontal sinus volumes and lateral lamella angles were significant. Males had larger frontal sinus volumes and higher lateral lamella angles than females (Table 2 ). Table 2 Comparison of frontal sinus volume and lateral lamella angle between males and females Mean ± Standard deviation P-value Male Female Right frontal sinus volume (mm 3 ) 4,116.3 ± 2,662.9 2,270.2 ± 1,941.8 < 0.001 Left frontal sinus volume (mm 3 ) 4,800.8 ± 3,089.2 2,672.5 ± 2,166.5 < 0.001 Right lateral lamella angle 68.6 ± 11.9 62.7 ± 11.3 0.002 Left lateral lamella angle 72.7 ± 9.9 67.4 ± 11.4 < 0.001 The majority of subjects with Gera class I lateral lamella angles had hyperplastic frontal sinuses, while most subjects with Gera class III lateral lamella angles had hypoplastic or aplastic frontal sinuses. The P-values for the statistical analysis comparing frontal sinus pneumatization patterns with Gera classification are < 0.001 for both sides (Table 3 ). The correlation between frontal sinus volume and lateral lamella angle was found to be statistically significant (r = 0.741, P < 0.001), indicating a moderate positive correlation between the two variables. This suggests that as the frontal sinus volume increases, the lateral lamella angle tends to be higher (Fig. 3 ). Table 3 Co-distribution of frontal sinus pneumatization patterns and Gera classes of lateral lamella angles on both sides Gera classification P-value Frontal sinus pneumatization patterns Class I n (%) Class II n (%) Class III n (%) Right side Aplastic 0 (0%) 4 (3.5%) 4 (40%) < 0.001 Hypoplastic 1 (3.8%) 19 (16.7%) 2 (20%) Middle sized 2 (7.7%) 54 (47.4%) 3 (30%) Hyperplastic 23 (88.5%) 37 (32.5%) 1 (10%) Left side Aplastic 0 (0%) 5 (4.9%) 2 (50%) < 0.001 Hypoplastic 0 (0%) 16 (15.5%) 2 (50%) Middle sized 5 (11.6%) 46 (44.7%) 0 (0%) Hyperplastic 38 (88.4%) 36 (35%) 0 (0%) Discussion Over the past century, radiological evaluation of the frontal sinus has been sustained for forensic and clinical purposes [ 9 , 11 , 26 – 28 , 30 ]. Guerram classification system is one of the most popular methods for classifying frontal sinus pneumatization patterns [ 9 ]. However, two-dimensional methods are not adequate in estimating the asymmetric and irregular three-dimensional extension of the frontal sinus and cannot provide the depth dimension. With advancements in imaging technology, the frontal sinus is increasingly being studied using three-dimensional reconstruction analysis [ 11 , 21 , 28 , 30 ]. Aslier et al. suggested a more reliable and precise method for grouping frontal sinus pneumatization patterns using computed tomography volumetric analysis [ 28 ]. In agreement with our results, they found that most frontal sinuses were hyperplastic (44.5%), followed by medium-sized (37.2%), while aplasia was found in 4.1%. We analyzed frontal sinus volume differences in relation to gender, age, and side variations. Significantly higher values were noted in males; however, age did not affect volumetric measurements. In a similar manner to our results, Hacl et al. reported mean volumes of 3.423 mm 3 and 3.945 mm 3 on the right and left sides, respectively but this difference did not reach statistical significance [ 11 ]. In their study, Aslier et al. found that the left frontal sinus volume was significantly larger than the right [ 28 ]. Males and young adults had significantly larger frontal sinuses according to Park et al. [ 21 ]. Several studies have suggested that certain variations of the anterior skull base may increase the risk of iatrogenic injuries during endoscopic sinus surgery [ 1 , 8 , 14 , 15 , 19 , 20 , 25 ]. In 1962, Keros et al. proposed a classification system using the depth of the cribriform plate to determine their vulnerability to iatrogenic injuries [ 15 ]. Nevertheless, many authors emphasize that more needs to be evaluated than just the depth of the cribriform plate, since this comprises only the medial portion of the anterior skull base, whereas the lateral portion is angulated [ 3 , 6 , 12 , 13 , 22 – 24 ]. Gera et al. predicted the hypothetical iatrogenic injury risk based on the angle formed between the lateral lamella of the cribriform plate and the horizontal plane in continuation with the cribriform plate [ 8 ]. Comparing the two methods, Gera classification was found to be more sensitive than Keros classification; however, both measurements demonstrated positive correlations [ 6 , 8 , 16 , 22 , 24 ]. It is important to consider how the extent of frontal sinus pneumatization affects adjacent structures. Researchers have examined the effect of frontal sinus pneumatization on the height of the anterior skull base and have found that greater pneumatization of the frontal sinus is associated with a deeper cribriform plate, and a deeper cribriform plate increases the risk of surgical complications [ 2 , 4 , 6 , 10 ]. We found that frontal sinus volume affects the lateral lamella angle. A larger frontal sinus is associated with a higher angle and a lower risk of iatrogenic injury as a result. In other words, a larger frontal sinus is associated with a deeper cribriform plate (a higher risk situation according to Keros) and a higher lateral lamella angle (a lower risk situation according to Gera) (Fig. 4 ). Consequently, the anterior skull base must be carefully assessed using both methods. In accordance with previous studies, Gera class II lateral lamella angles (72.3%) were the most common. Table 4 summarizes the distribution of Gera classification in previous reports [ 1 , 6 , 8 , 16 , 18 , 24 ]. In terms of gender, males had significantly higher angles than females, but many authors did not observe such a difference [ 1 , 8 , 16 , 18 ]. Similar to Keşkek et al., age did not influence the lateral lamella angle [ 16 ]. Our results show that the left side has a significantly higher lateral lamella angle. Mahdian et al. reported significant differences between the right and left angles [ 18 ]. Lawson et al. and Freedman et al. studied over 1000 intranasal ethmoidectomies and found that right-sided operations had more complications [ 7 , 17 ]. They suggested that the position of a right-handed surgeon performing a right-sided ethmoidectomy may correlate with a higher incidence of right-sided surgical complications. Dessi et al. investigated the asymmetry of the ethmoid roof and found it to be lower on the right side, which may contribute to the higher injury rate [ 5 ]. Table 4 The distribution of Gera classification of lateral lamella angles in previous studies Author Sample size Class I (%) Class II (%) Class III (%) Abdullah et al. [ 1 ] 150 23.7% 72.3%, 4% Fadda et al. [ 6 ] 220 17.7% 77.5% 4.8% Gera et al. [ 8 ] 190 32.6% 62.7% 4.7% Keşkek et al. [ 16 ] 385 34.7% 63% 2.3% Mahdian et al. [ 18 ] 372 29.57% 61.42% 9.01% Sasmal et al [ 24 ] 600 11% 85% 4% Potential weaknesses of this study are the small sample size and retrospective design. The generalization of the results may be limited by the exclusion of subjects with frontal sinus or skull base pathology or previous surgery; however, these conditions could deform the anatomy and result in imprecise measurements. A future study may investigate how frontal sinus and skull base variations affect intraoperative and postoperative outcomes. The findings of this research provide a deeper understanding of the complex relationship between the frontal sinus and the anterior skull base. Larger frontal sinuses are associated with higher lateral lamella angles. Studies have also shown that larger frontal sinuses are associated with deeper cribriform plates [ 2 , 4 , 6 , 10 ]. A safe surgical approach requires awareness of these anatomical associations. Additionally, several parameters should be measured preoperatively to identify anatomical situations that may lead to complications. Conclusion Frontal sinus volume and lateral lamella angle are positively correlated. The lateral lamella angle of subjects with hypoplastic or aplastic frontal sinuses is lower and as a result they have a higher risk of iatrogenic injury. Understanding the complex anatomical relationship between the frontal sinus and anterior skull base is important to avoid serious surgical complications. Declarations Author Contribution: All listed authors have contributed substantially to protocol development, data collection, data analysis, and manuscript writing and editing. Acknowledgements: None. Funding: No funds, grants, or other support was received. Data availability: Data are available from the corresponding author upon reasonable request. Compliance with ethical standards Conflict of interest: The authors declare that they have no conflict of interest. Ethical approval: The Local Institutional Human Ethics Committee approved this retrospective study and waived the need for informed consent (IRB23-021). References Abdullah B, Chew SC, Aziz ME, Shukri NM, Husain S, Joshua SW, Wang DY, Snidvongs K (2020) A new radiological classification for the risk assessment of anterior skull base injury in endoscopic sinus surgery. Sci Rep 10:4600. https://doi.org/10.1038/s41598-020-61610-1 Atalay B, Eser MB (2021) The relation between the metopic suture persistence and frontal sinus volume and olfactory Fossa depth: A reliability study with semiautomatic volume measurement. 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Cite Share Download PDF Status: Published Journal Publication published 27 Nov, 2024 Read the published version in Surgical and Radiologic Anatomy → Version 1 posted Editorial decision: Revision requested 19 Jun, 2024 Reviews received at journal 06 May, 2024 Reviewers agreed at journal 06 May, 2024 Reviewers agreed at journal 05 May, 2024 Reviews received at journal 04 May, 2024 Reviewers agreed at journal 30 Apr, 2024 Reviews received at journal 30 Mar, 2024 Reviewers agreed at journal 25 Mar, 2024 Reviewers invited by journal 25 Mar, 2024 Editor assigned by journal 01 Feb, 2024 Submission checks completed at journal 31 Jan, 2024 First submitted to journal 28 Jan, 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. 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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-3906574","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":270462615,"identity":"1ced6238-58a0-4286-acc9-9b1a929b5eb7","order_by":0,"name":"Mona Alrehaili","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7UlEQVRIiWNgGAWjYLACCSjNzFABIpkbCGuxgGs5AyIZidBSAdPC2AaiCGjRbe89+OHmHht7fvazDz8XzquN5m8HavlRsQ2nFrMz55IlZzxLS5zZk24sPXPb8dwZhxkbGHvO3Mat5UaOgbTEgcMJBgfS2Jh5tx3LbQBqAboQrxbj338O/Le3P/8MqGXOsdz5RGgxk5A4cIBxgwTIloaa3A0EtZw5Y2YhcSA5ccaNZ8zSPMcO5G4EajmI1y/He4xvSByws+fvT2P8zFNTlzvv/OGDD35U4NaCDg6DyQNEqweCOlIUj4JRMApGwQgBAEkXWxAQkrohAAAAAElFTkSuQmCC","orcid":"","institution":"King Salman Bin Abdulaziz Medical City","correspondingAuthor":true,"prefix":"","firstName":"Mona","middleName":"","lastName":"Alrehaili","suffix":""},{"id":270462616,"identity":"4fa9779c-19e9-439b-bc79-29a6ea4ff6c5","order_by":1,"name":"Sara T Alharbi","email":"","orcid":"","institution":"King Salman Bin Abdulaziz Medical City","correspondingAuthor":false,"prefix":"","firstName":"Sara","middleName":"T","lastName":"Alharbi","suffix":""},{"id":270462617,"identity":"115eb73d-4ac9-4f34-828b-9689067a7188","order_by":2,"name":"Omar Ali A Alharbi","email":"","orcid":"","institution":"King Salman Bin Abdulaziz Medical City","correspondingAuthor":false,"prefix":"","firstName":"Omar","middleName":"Ali A","lastName":"Alharbi","suffix":""},{"id":270462618,"identity":"3bf8351a-d302-41b4-b244-47c62475e311","order_by":3,"name":"Bandar Alluhaybi","email":"","orcid":"","institution":"King Salman Bin Abdulaziz Medical City","correspondingAuthor":false,"prefix":"","firstName":"Bandar","middleName":"","lastName":"Alluhaybi","suffix":""}],"badges":[],"createdAt":"2024-01-28 18:44:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3906574/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3906574/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00276-024-03514-7","type":"published","date":"2024-11-27T15:58:33+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":50568102,"identity":"2052e170-12be-402c-8039-088d4cc0074f","added_by":"auto","created_at":"2024-02-02 15:24:02","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1087928,"visible":true,"origin":"","legend":"\u003cp\u003eComputed tomography reconstruction and 3D model of the segmented frontal sinuses. (a) axial, (b) coronal, and (c) sagittal planes (d) three-dimensional volume of the frontal sinuses. Red color indicates the left and blue indicates the right frontal sinuses.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3906574/v1/5b5106eaba6350248127b908.png"},{"id":50569458,"identity":"56d719a7-f058-4235-bfbc-9382e4abe66e","added_by":"auto","created_at":"2024-02-02 15:32:02","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":503123,"visible":true,"origin":"","legend":"\u003cp\u003eThe angle formed between the lateral lamella of the cribriform plate (solid line) and the horizontal plane in continuation with the cribriform plate (dashed line)\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3906574/v1/40a99b977a9cb907cdda386f.png"},{"id":50568104,"identity":"0ba81a41-19b5-444e-8667-bb06f0dfbf77","added_by":"auto","created_at":"2024-02-02 15:24:02","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":850136,"visible":true,"origin":"","legend":"\u003cp\u003eScatterplot demonstrating the relation between frontal sinus volume and lateral lamella angle\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-3906574/v1/a9d078fc6d09d3477ce01ee8.png"},{"id":50568101,"identity":"4299b1d7-8747-40f4-a100-7405199e5e71","added_by":"auto","created_at":"2024-02-02 15:24:02","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":133887,"visible":true,"origin":"","legend":"\u003cp\u003eSummary of the correlational relationship between frontal sinus pneumatization and anterior skull base height and angel\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-3906574/v1/ee26fe2635aba83f713862af.png"},{"id":70389437,"identity":"5b078992-8a74-4bf8-9d80-8ce6e8ccfa07","added_by":"auto","created_at":"2024-12-02 17:28:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2380889,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3906574/v1/a9177309-aa9a-4dc7-beb9-a6f7cf8339a2.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Computed Tomography Volumetric Analysis of Frontal Sinus Pneumatization and its Effect on Lateral Lamella Angle","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEndoscopic sinus surgery is an effective treatment for paranasal sinus diseases. Although the procedure is minimally invasive, there are risks of cerebrospinal fluid leaks, orbital, intracranial and vascular injuries. In most cases, major complications occur due to variations in the skull base and paranasal sinus anatomy [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Preoperative computed tomography is essential in assessing the risk of these variations.\u003c/p\u003e \u003cp\u003eFrontal sinuses are surgically important for many reasons, including their proximity to the skull base and orbits, their complex and variable morphology, and the effect of their pneumatization on neighboring structures. Frontal sinus pneumatization patterns have been classified based on two- and three-dimensional views [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan additionalcitationids=\"CR27\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Volumetric measurements can be obtained through three-dimensional reconstruction analysis, which allows for more accurate categorization of pneumatization patterns [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe anterior skull base is composed of the cribriform plate and fovea ethmoidalis; these two parts are connected via the sloping lateral lamella of the cribriform plate, which is the most delicate and vulnerable part of the skull base [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Several studies have linked certain anatomical variations, such as a steep or low-lying anterior skull base, to a higher risk of surgical complications [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe effect of frontal sinus pneumatization on the height of the cribriform plate has been investigated in the past [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, determining iatrogenic injury risk based solely on the height of the skull base is not sufficient without considering its sloped configuration. This is the first study investigating the effect of frontal sinus volume on the lateral lamella angle. Additionally, we aimed to examine the differences in frontal sinus volume and lateral lamella angle according to gender, age, and side variations.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSubjects and computed tomography imaging\u003c/h2\u003e \u003cp\u003eThis retrospective study included 150 computed tomography scans of paranasal sinuses (300 sides) retrieved from the Picture Archiving and Communication System (PACS) of the radiology department at King Salman bin Abdulaziz Medical City in Medina, Saudi Arabia. The Local Institutional Human Ethics Committee reviewed and approved the study protocol.\u003c/p\u003e \u003cp\u003eImages were acquired using Aquilion Prime SP CT scan system from Canon Medical Systems\u0026reg;; a dual-energy CT scanner with radiation tubes that can complete a full rotation in 0.35 seconds and scan up to four centimeters of anatomy per one tube rotation in a range of 80 to 135 kVp. A pre-equipped scanning protocol was used. An average of 60 two-mm slices were obtained per scan. The axial, coronal, and sagittal planes were automatically reconstructed into 0.5 mm soft tissue and bone window slices. Radiation factors were defined and controlled automatically by the automatic exposure control (AEC).\u003c/p\u003e \u003cp\u003eTo ensure the accuracy of all acquired measurements, we excluded subjects under 19 years of age. We also excluded inflamed sinuses, sinonasal tumors and polyposis, previous surgery or trauma, congenital craniofacial skeletal abnormalities, skull base pathology or defects, and scans with inadequate technical quality.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eData processing and radiological measurements\u003c/h2\u003e \u003cp\u003eData processing was implemented using ITK-SNAP software (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e\u003ca href=\"http://www.itksnap.org\" target=\"_blank\"\u003ewww.itksnap.org\u003c/a\u003e\u003c/span\u003e\u003cspan address=\"http://www.itksnap.org\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e), version 3.8.0, which is an open-source tool capable of segmenting images, analyzing data, and creating 3D shapes [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. The processing begins by contouring both right and left frontal sinuses using the active contour tool, which can create a region of interest defined by the user on axial, coronal, and sagittal planes to trigger automatic segmentation for each frontal sinus separately. Then, volume (mm\u003csup\u003e3\u003c/sup\u003e), voxel count, and intensity mean were obtained automatically using the volume and statistics tool (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eBased on volumetric cutoff values suggested by Aslier et al., the frontal sinus pneumatization patterns were categorized into four groups: aplastic (no pneumatization), hypoplastic (less than 1131.25 mm\u003csup\u003e3\u003c/sup\u003e), middle-sized (1131.25 mm\u003csup\u003e3\u003c/sup\u003e to 3328.50 mm\u003csup\u003e3\u003c/sup\u003e) and hyperplastic (more than 3328.50 mm\u003csup\u003e3\u003c/sup\u003e) [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe angle formed between the lateral lamella of the cribriform plate and the horizontal plane in continuation with the cribriform plate was measured in coronal view (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). According to Gera classification, the angles were divided into three classes based on the hypothetical risk of iatrogenic injury: Class I (more than 80 degrees, low risk), Class II (45 to 80 degrees, medium risk), and Class III (less than 45 degrees, high risk) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe statistical analysis was performed using SPSS version 29.0. Descriptive statistics were utilized to analyze patient demographics, lateral lamella angle, and frontal sinus volume. The Mann-Whitney U test was used to compare frontal sinus volume and lateral lamella angle between genders. Non-parametric correlation analysis, using Spearman rank-order, was applied to examine the relationship between frontal sinus volume and lateral lamella angle. Statistical significance was set at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 150 computed tomography scans of paranasal sinuses (300 sides) were analyzed, ranging in age from 19 to 73 years, with a mean age of 35\u0026thinsp;\u0026plusmn;\u0026thinsp;12 years. Of the subjects included, 53.3% were males and 46.7% were females. Most of the frontal sinuses were hyperplastic, accounting for 45%. Middle-sized frontal sinuses (36.7%) were also common. Aplasia was observed in 5% of the examined frontal sinuses. In most subjects (72.3%), lateral lamella angles ranged from 45 to 80 degrees (Gera Class II). 4.7% of subjects had lateral lamella angles less than 45 degrees (Gera class III) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe distribution of frontal sinus pneumatization patterns and Gera classes of lateral lamella angles\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003cp\u003e\u003cem\u003en (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRight side\u003c/p\u003e \u003cp\u003e\u003cem\u003en (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLeft side\u003c/p\u003e \u003cp\u003e\u003cem\u003en (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eFrontal sinus pneumatization pattern\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 (5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8 (5.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7 (4.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypoplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40 (13.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22 (14.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18 (12%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiddle-sized\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e110 (36.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e59 (39.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51 (34%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyperplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e135 (45%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e61 (40.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e74 (49.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eLateral lamella angle\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClass I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e69 (23%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e43 (28.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26 (17.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClass II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e217 (72.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e103 (68.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e114 (76%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClass III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (4.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4 (2.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10 (6.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe mean frontal sinus volume was 3,254.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2,521.8 mm\u003csup\u003e3\u003c/sup\u003e and 3,807.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2,892.8 mm\u003csup\u003e3\u003c/sup\u003e on the right and left sides respectively; however, this difference did not reach statistical significance. The mean angle measured at the lateral lamella and the horizontal plane in continuation with the cribriform plate was 65.8\u0026thinsp;\u0026plusmn;\u0026thinsp;12 on the right side and 70.2\u0026thinsp;\u0026plusmn;\u0026thinsp;10.9 on the left side. The angle was significantly higher on the left side (P-value\u0026thinsp;=\u0026thinsp;0.001). The analysis showed no statistically significant differences in frontal sinus volume and lateral lamella angle according to age. Gender differences in frontal sinus volumes and lateral lamella angles were significant. Males had larger frontal sinus volumes and higher lateral lamella angles than females (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of frontal sinus volume and lateral lamella angle between males and females\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard deviation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight frontal sinus volume (mm\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4,116.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2,662.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2,270.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1,941.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft frontal sinus volume (mm\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4,800.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3,089.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2,672.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2,166.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight lateral lamella angle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e68.6\u0026thinsp;\u0026plusmn;\u0026thinsp;11.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e62.7\u0026thinsp;\u0026plusmn;\u0026thinsp;11.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft lateral lamella angle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e72.7\u0026thinsp;\u0026plusmn;\u0026thinsp;9.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e67.4\u0026thinsp;\u0026plusmn;\u0026thinsp;11.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe majority of subjects with Gera class I lateral lamella angles had hyperplastic frontal sinuses, while most subjects with Gera class III lateral lamella angles had hypoplastic or aplastic frontal sinuses. The P-values for the statistical analysis comparing frontal sinus pneumatization patterns with Gera classification are \u0026lt;\u0026thinsp;0.001 for both sides (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The correlation between frontal sinus volume and lateral lamella angle was found to be statistically significant (r\u0026thinsp;=\u0026thinsp;0.741, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), indicating a moderate positive correlation between the two variables. This suggests that as the frontal sinus volume increases, the lateral lamella angle tends to be higher (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCo-distribution of frontal sinus pneumatization patterns and Gera classes of lateral lamella angles on both sides\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eGera classification\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFrontal sinus pneumatization patterns\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eClass I\u003c/p\u003e \u003cp\u003e\u003cem\u003en (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eClass II\u003c/p\u003e \u003cp\u003e\u003cem\u003en (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eClass III\u003c/p\u003e \u003cp\u003e\u003cem\u003en (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eRight side\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (3.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypoplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (3.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19 (16.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (20%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiddle sized\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (7.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e54 (47.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (30%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyperplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23 (88.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37 (32.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (10%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eLeft side\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (4.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (50%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypoplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (15.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (50%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiddle sized\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (11.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e46 (44.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyperplastic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38 (88.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36 (35%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOver the past century, radiological evaluation of the frontal sinus has been sustained for forensic and clinical purposes [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan additionalcitationids=\"CR27\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Guerram classification system is one of the most popular methods for classifying frontal sinus pneumatization patterns [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. However, two-dimensional methods are not adequate in estimating the asymmetric and irregular three-dimensional extension of the frontal sinus and cannot provide the depth dimension. With advancements in imaging technology, the frontal sinus is increasingly being studied using three-dimensional reconstruction analysis [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAslier et al. suggested a more reliable and precise method for grouping frontal sinus pneumatization patterns using computed tomography volumetric analysis [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. In agreement with our results, they found that most frontal sinuses were hyperplastic (44.5%), followed by medium-sized (37.2%), while aplasia was found in 4.1%. We analyzed frontal sinus volume differences in relation to gender, age, and side variations. Significantly higher values were noted in males; however, age did not affect volumetric measurements. In a similar manner to our results, Hacl et al. reported mean volumes of 3.423 mm\u003csup\u003e3\u003c/sup\u003e and 3.945 mm\u003csup\u003e3\u003c/sup\u003e on the right and left sides, respectively but this difference did not reach statistical significance [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In their study, Aslier et al. found that the left frontal sinus volume was significantly larger than the right [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Males and young adults had significantly larger frontal sinuses according to Park et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSeveral studies have suggested that certain variations of the anterior skull base may increase the risk of iatrogenic injuries during endoscopic sinus surgery [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. In 1962, Keros et al. proposed a classification system using the depth of the cribriform plate to determine their vulnerability to iatrogenic injuries [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Nevertheless, many authors emphasize that more needs to be evaluated than just the depth of the cribriform plate, since this comprises only the medial portion of the anterior skull base, whereas the lateral portion is angulated [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan additionalcitationids=\"CR23\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Gera et al. predicted the hypothetical iatrogenic injury risk based on the angle formed between the lateral lamella of the cribriform plate and the horizontal plane in continuation with the cribriform plate [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Comparing the two methods, Gera classification was found to be more sensitive than Keros classification; however, both measurements demonstrated positive correlations [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIt is important to consider how the extent of frontal sinus pneumatization affects adjacent structures. Researchers have examined the effect of frontal sinus pneumatization on the height of the anterior skull base and have found that greater pneumatization of the frontal sinus is associated with a deeper cribriform plate, and a deeper cribriform plate increases the risk of surgical complications [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. We found that frontal sinus volume affects the lateral lamella angle. A larger frontal sinus is associated with a higher angle and a lower risk of iatrogenic injury as a result. In other words, a larger frontal sinus is associated with a deeper cribriform plate (a higher risk situation according to Keros) and a higher lateral lamella angle (a lower risk situation according to Gera) (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Consequently, the anterior skull base must be carefully assessed using both methods.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn accordance with previous studies, Gera class II lateral lamella angles (72.3%) were the most common. Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e summarizes the distribution of Gera classification in previous reports [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In terms of gender, males had significantly higher angles than females, but many authors did not observe such a difference [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Similar to Keşkek et al., age did not influence the lateral lamella angle [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Our results show that the left side has a significantly higher lateral lamella angle. Mahdian et al. reported significant differences between the right and left angles [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Lawson et al. and Freedman et al. studied over 1000 intranasal ethmoidectomies and found that right-sided operations had more complications [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. They suggested that the position of a right-handed surgeon performing a right-sided ethmoidectomy may correlate with a higher incidence of right-sided surgical complications. Dessi et al. investigated the asymmetry of the ethmoid roof and found it to be lower on the right side, which may contribute to the higher injury rate [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe distribution of Gera classification of lateral lamella angles in previous studies\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAuthor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSample size\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eClass I (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eClass II (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eClass III (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbdullah et al. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.7%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e72.3%,\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFadda et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e220\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.7%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e77.5%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.8%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGera et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e190\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.6%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e62.7%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.7%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKeşkek et al. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e385\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34.7%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.3%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMahdian et al. [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e372\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29.57%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61.42%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.01%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSasmal et al [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e85%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePotential weaknesses of this study are the small sample size and retrospective design. The generalization of the results may be limited by the exclusion of subjects with frontal sinus or skull base pathology or previous surgery; however, these conditions could deform the anatomy and result in imprecise measurements. A future study may investigate how frontal sinus and skull base variations affect intraoperative and postoperative outcomes.\u003c/p\u003e \u003cp\u003eThe findings of this research provide a deeper understanding of the complex relationship between the frontal sinus and the anterior skull base. Larger frontal sinuses are associated with higher lateral lamella angles. Studies have also shown that larger frontal sinuses are associated with deeper cribriform plates [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. A safe surgical approach requires awareness of these anatomical associations. Additionally, several parameters should be measured preoperatively to identify anatomical situations that may lead to complications.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eFrontal sinus volume and lateral lamella angle are positively correlated. The lateral lamella angle of subjects with hypoplastic or aplastic frontal sinuses is lower and as a result they have a higher risk of iatrogenic injury. Understanding the complex anatomical relationship between the frontal sinus and anterior skull base is important to avoid serious surgical complications.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contribution:\u0026nbsp;\u003c/strong\u003eAll listed authors have contributed substantially to protocol development, data collection, data analysis, and manuscript writing and editing.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eNo funds, grants, or other support was received.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u003c/strong\u003e Data are available from the corresponding author upon reasonable request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompliance with ethical standards\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest:\u003c/strong\u003e The authors declare that they have no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval:\u003c/strong\u003e The Local Institutional Human Ethics Committee approved this retrospective study and waived the need for informed consent (IRB23-021).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbdullah B, Chew SC, Aziz ME, Shukri NM, Husain S, Joshua SW, Wang DY, Snidvongs K (2020) A new radiological classification for the risk assessment of anterior skull base injury in endoscopic sinus surgery. 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Int J Legal Med 135:1015\u0026ndash;1023. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00414-020-02443-5\u003c/span\u003e\u003cspan address=\"10.1007/s00414-020-02443-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"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":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Frontal sinus, Lateral lamella, Computed tomography, Volumetry, Endoscopic sinus surgery","lastPublishedDoi":"10.21203/rs.3.rs-3906574/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3906574/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eAnatomical associations between the frontal sinus and anterior skull base must be carefully understood in preoperative imaging to minimize surgical complications. This study aims to investigate the relationship between frontal sinus volume and lateral lamella angle.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003e150 computed tomography scans of paranasal sinuses (300 sides) were retrospectively reviewed. Pneumatization patterns were classified according to volume using a three-dimensional reconstruction analysis of the frontal sinuses. The angle formed between the lateral lamella and the horizontal plane in continuation with the cribriform plate was measured and grouped according to Gera classification based on the hypothetical risk of iatrogenic injury. Analysis of these measurements was conducted.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA positive correlation was found between frontal sinus volume and lateral lamella angle. Hyperplastic frontal sinuses were the most prevalent followed by middle-sized sinuses. 5% of the frontal sinuses were aplastic. Lateral lamella angles ranging from 45 to 80 degrees (Gera class II) were the most common. Aplastic and hypoplastic frontal sinuses were common in subjects with less than 45 degrees lateral lamella angles (Gera class III). Males had significantly higher frontal sinus volumes and lateral lamella angles than females, while the influence of age was insignificant. Lateral lamella angles were significantly higher on the left side.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe frontal sinus volume affects the lateral lamella angle. Larger frontal sinuses are associated with higher lateral lamella angles and vice versa. Understanding this anatomical relationship can help prevent surgical complications.\u003c/p\u003e","manuscriptTitle":"Computed Tomography Volumetric Analysis of Frontal Sinus Pneumatization and its Effect on Lateral Lamella Angle","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-02 15:23:58","doi":"10.21203/rs.3.rs-3906574/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-06-19T07:38:04+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-06T13:54:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"62548250107176841716392144386263353988","date":"2024-05-06T10:07:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"148305007778284593490652216397235354506","date":"2024-05-05T09:47:18+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-05T01:30:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"226554591198558087879895054541864809554","date":"2024-04-30T07:01:56+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-03-30T16:59:12+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"51dbc09e-9a04-423c-82f4-c64bc72cea64","date":"2024-03-25T12:24:49+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-03-25T09:32:13+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-02-01T13:03:01+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-02-01T01:57:42+00:00","index":"","fulltext":""},{"type":"submitted","content":"Surgical and Radiologic Anatomy","date":"2024-01-28T18:40:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"6c981ec9-c496-4255-8dec-f46b3ea0a942","owner":[],"postedDate":"February 2nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-12-02T17:24:09+00:00","versionOfRecord":{"articleIdentity":"rs-3906574","link":"https://doi.org/10.1007/s00276-024-03514-7","journal":{"identity":"surgical-and-radiologic-anatomy","isVorOnly":false,"title":"Surgical and Radiologic Anatomy"},"publishedOn":"2024-11-27 15:58:33","publishedOnDateReadable":"November 27th, 2024"},"versionCreatedAt":"2024-02-02 15:23:58","video":"","vorDoi":"10.1007/s00276-024-03514-7","vorDoiUrl":"https://doi.org/10.1007/s00276-024-03514-7","workflowStages":[]},"version":"v1","identity":"rs-3906574","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3906574","identity":"rs-3906574","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}