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Objectives: To compare the mean deflection angles as well as the anterior and posterior lengths of the cranial base in different sagittal skeletal patterns., Methods: The cross-sectional study was conducted at the Department of Orthodontics, Sharif Medical and Dental College, Jati Umrah, Lahore, Pakistan, from December 2022 to May 2023, and comprised orthodontic patients of either gender aged 8-20 years. Pre-treatment lateral cephalograms of the patients were traced on lead acetate tracing sheet with 0.03mm mechanical pencil. Outcome variables for the cranial base nasion-sella-articulare, nasionsella- basion, nasion-sella and sella-basion were recorded, and data was stratified for age and gender. Data was analysed using SPSS 23., Results: Of the 93 patients, 60(64.5%) were females and 33(35.5%) were males. The overall mean age was 15.6±3.0 years, 38(40.9%) aged 8-14 years and 55(59.1%) aged 15-20 years. Mean values of cranial base flexion nasion-sellaarticulare, nasion-sella-basion and posterior cranial base length sella-basion were significant in different sagittal patterns (p<0.05). Gender-based differences in mean values of anterior and posterior cranial base lengths were significant (p<0.05)., Conclusions: Cranial base flexion decreased significantly in skeletal class III. Cranial base lengths were higher for males than females, while age had no effect on cranial base morphology.

Acquired skull base cerebrospinal fluid (CSF) leaks can result from trauma, tumors, iatrogenic causes, or may be spontaneous. Spontaneous skull base CSF leaks are likely a manifestation of underlying idiopathic intracranial hypertension. The initial assessment of rhinorrhea or otorrhea, which may be suspected owing to an acquired skull base CSF leak, requires integration of clinical assessment and biochemical confirmation of CSF. When leaks are multiple or if samples of fluid cannot be obtained for testing, then recourse to intrathecal contrast-enhanced cisternography may be necessary. We also review various other applications for diagnosis of intracranial abnormalities using contrast-enhanced cisternography., Competing Interests: Disclosure The authors have no commercial or financial conflicts of interests to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: This study aimed to predict long-term growth-related changes in skeletal and dental relationships within the craniofacial complex using machine learning (ML) models., Materials and Methods: Cephalometric radiographs from 301 subjects, taken at pre-pubertal (T1, age 11) and post-pubertal stages (T2, age 18), were analysed. Three ML models-Lasso regression, Random Forest, and Support Vector Regression (SVR)-were trained on a subset of 240 subjects, while 61 subjects were used for testing. Model performance was evaluated using mean absolute error (MAE), intraclass correlation coefficients (ICCs), and clinical thresholds (2 mm or 2°)., Results: MAEs for skeletal measurements ranged from 1.36° (maxilla to cranial base angle) to 4.12 mm (mandibular length), and for dental measurements from 1.26 mm (lower incisor position) to 5.40° (upper incisor inclination). ICCs indicated moderate to excellent agreement between actual and predicted values. The highest prediction accuracy within the 2 mm or 2° clinical thresholds was achieved for maxilla to cranial base angle (80%), lower incisor position (75%), and maxilla to mandible angle (70%). Pre-pubertal measurements and sex consistently emerged as the most important predictive factors., Conclusions: ML models demonstrated the ability to predict post-pubertal values for maxilla to cranial base, mandible to cranial base, maxilla to mandible angles, upper and lower incisor positions, and upper face height with a clinically acceptable margin of 2 mm or 2°. Prediction accuracy was higher for skeletal relationships compared to dental relationships over the 8-year growth period. Pre-pubertal values of the measurements and sex emerged consistently as the most important predictors of the post-pubertal values., Competing Interests: Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: Allergic fungal rhinosinusitis (AFRS) often results in expansion of disease beyond the paranasal sinuses, which may put important structures, such as the anterior ethmoid artery (AEA) or lateral lamella of the cribiform, at risk of injury during endoscopic sinus surgery (ESS). This study aims to compare the AEA to skull base (AEA-SB) length in patients with AFRS versus chronic rhinosinusitis with nasal polyps (CRSwNP), as well as additional anatomic variants., Methods: A single institutional retrospective chart review of patients undergoing ESS for AFRS and CRSwNP was performed. AEA-SB length were compared between the 2 groups. Other anatomic variants, including Keros measurement and presence of supraorbital ethmoid air cells (SOEC), concha bullosa (CB), sphenoethmoidal, and infraorbital ethmoid cells were measured and compared between the 2 groups., Results: Twenty-one patients were included in each cohort. The AFRS group was younger in age ( P  = .015) and had a significantly longer AEA-SB length ( P  = .014) compared to the CRSwNP group. No significant differences were observed between the 2 groups regarding Keros measurement, presence of concha bullosa, infraorbital ethmoid, sphenoethmoidal, or SOEC. No association was seen between AEA-SB length and Keros class in either group., Conclusions: AFRS harbors anatomical differences when compared to CRSwNP, with the former associated with a longer AEA-SB length. This key difference should be considered in preoperative planning to prevent injury to the AEA in patients undergoing ESS for AFRS., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Philip Chen recieves consulting fees from Medtronic, speaking honoraria from GlaxoSmithKline and Optinose, and research funding from Aerin Medical.

The skull base and orbit have complicated anatomical structures where various tumors can occur. The tumor may present with neurological symptoms; however, its diagnosis is clinically difficult owing to accessibility issues. Therefore, diagnostic imaging is crucial in assessing tumors in the skull base and orbit and guiding subsequent management. Notably, some tumors have a predilection for a specific site of origin, and identifying the site of origin on imaging can help narrow the differential diagnosis. At the skull base, chordomas typically occur in the clivus, chondrosarcomas in the paramedian areas, paragangliomas in the jugular foramen, neurogenic tumors, and perineural spread in the neural foramen. Among orbital tumors, cavernous hemangiomas usually occur in the intraconal space, and pleomorphic adenomas and adenoid cystic carcinomas occur in the lacrimal glands. Some skull base and orbital tumors exhibit distinctive imaging features. Chordomas and chondrosarcomas of the skull base show high signal intensities on T2-weighted images, with chondrosarcomas often displaying cartilaginous calcifications. Paragangliomas are characterized by their hypervascular nature. In the orbit, cavernous hemangiomas and pleomorphic adenomas present unique dynamic patterns. Immunoglobulin G4-related disease forms lesions along the nerves. Identifying the tumor origin and its imaging characteristics can help narrow the differential diagnosis of skull base and orbital tumors., Competing Interests: Declarations. Conflict of interest: The authors have no competing interests to declare that are relevant to the content of this article. Ethical approval: This article contains no studies with human participants or animals performed by any of the authors., (© 2024. The Author(s).)

The aim of this cross-sectional study was to perform a three-dimensional (3D) assessment of the cranial base of patients with unilateral cleft lip and palate (UCLP). Cone-beam computed tomography (CBCT) scans of 52 UCLP patients (21 females and 31 males; mean age, 10.0 ± 2.12 years) were compared with the scans of 72 individuals (24 females and 48 males; mean age, 11.0 ± 2.11 years) without CLP, matched by gender and age (control group, CG). The 3D Euclidean distances of anterior cranial base (N-S), posterior cranial base (S-Ba), total cranial base (N-Ba) lengths, cranial base width (Po-Po), as well as the cranial base flexure (NSBa), were measured using open-source software ITK-SNAP and 3D Slicer. Statistical analyses were carried out with the Student's t-test at a significance level of 5%. UCLP demonstrated shorter 3D distances than CG in the N-S, S-Ba, and N-Ba cranial base lengths (p < 0.001). In comparison with female CG, female UCLP had a smaller cranial base flexure (NSBa; p = 0.020). No statistically significant differences between UCLP and CG were found for the cranial base width (Po-Po). UCLP patients presented distinct morphological cranial base characteristics in comparison with CG. These results indicate that morphological and positioning changes in the maxillary bones are not solely attributable to the cleft and/or surgical procedures.

Background: The skull base ligaments have been extensively studied in the literature due to their clinical and surgical significance. The posterior petroclinoid fold (PPCNF) and petroclival ligament (PCVL) are two adjacent structures that have barely been studied and are frequently confused. The present study uses an innovative classification system to investigate the PPCNF and PCVL ossification patterns., Materials: An archive of 164 computed tomography (CT) scans (328 sides) was evaluated. The sexes were distributed as follows: 86 females and 78 males. The mean age was 47.78 ± 15.64 years old. The ossification patterns were classified as follows: Type 0 (no ossification), Type 1 (incomplete ossification), Type 2 (complete ossification). The incomplete ossification was further classified as subtype 1a (ossification from the clival region), subtype 1b (ossification from the petrous region), and subtype 1c (ossification from both regions)., Results: No PPCNF ossification was observed in 72.6% (238/328 sides). Incomplete PPCNF ossification was identified in 25.8% (85/328 sides), and complete ossification in 1.5% (5/328 sides). A male predominance was determined for the PPCNF ossification. No PCVL ossification was observed in 85.4% (280/328 sides). Incomplete PCVL ossification was observed in 8.2% (27/328 sides) and complete ossification in 6.4% (21/328 sides). The age affected the PCVL ossification, with the older patients presenting with ossification. Simultaneous absence of PPCNF and PCVL ossification was observed in 215 sides (65.5%). The coexistence of incomplete PPCNF and PCVL ossified variants was identified in 13 sides (4%). Concomitant complete PPCNF and PCVL ossified variants were detected in 2 sides (0.6%)., Conclusions: The current study presents a detailed description of the PPCNF and PCVL. Knowledge of both structures' ossification is important for anatomists, radiologists, and clinicians due to their close relationship with neurovascular structures., Competing Interests: Declarations. Ethical approval and consent to participate: Ethical approval and consent to participate The Ethics Committee of the General Hospital of Nikaia-Piraeus approved the study. The research was conducted ethically according to the Code of Ethics of the World Medical Association (Declaration of Helsinki). The cadaveric head belongs to the Department of Anatomy (School of Medicine, National and Kapodistrian University of Athens). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: This report analyzes traumatic anterior skull base CSF leaks following nasopharyngeal swab testing for detection of SARS-CoV-2 in the largest case series to date, combined with a systematic literature review., Methods: Retrospective multi-institutional case-series of traumatic anterior skull base CSF leak with clear antecedent history of COVID-19 swab was completed. A comprehensive search of databases was performed for the systematic literature review., Results: Thirty-four patients with traumatic CSF leak after COVID-19 nasopharyngeal swab testing were identified. Women were more than twice as likely to experience a CSF leak, as compared to men. The majority of patients (58.8%) had no reported predisposing factor in their clinical history. Common defect sites included the cribriform plate (52.9%), sphenoid sinus (29.4%), and ethmoid roof (17.6%). Four patients (11.8%) presented with meningitis. The median time between the traumatic COVID swab and the detection of CSF leak was 4 weeks (IQR 1-9). Patients with meningitis had a median leak duration of 12 weeks (IQR 8-18). The average leak duration was significantly longer in patients with meningitis compared to without meningitis (p = 0.029), with a moderate effect size (r = - 0.68). Most cases (92.9%) managed with endoscopic endonasal surgical repair were successful., Conclusions: This report clarifies the presentation, risk factors, and management of CSF leaks attributable to diagnostic nasopharynx swabbing procedures in the COVID-19 era. Timely surgical repair is the recommended management option for such leaks., Competing Interests: Declarations. Conflict of interest: The authors declare no conflicts of interest. Ethical approval: This study was performed in compliance with the Helsinki Declaration. This study was deemed exempt from review by the Helsinki committee of the University of Arizona/Banner—University Medical Center Tucson. (2023-HSF1309)., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To determine alterations in the crista galli (CG) size in fetuses with advancing weeks., Methods: Skull bases of 32 fetuses (11 males/21 females) aged 17 to 32 weeks in utero were included in the study. The width (width of CG), height (height of CG), and length (length of CG) of CG were measured, and also olfactory fossa depth (OFD) was measured to determine the relation of CG with OFD., Results: Width of CG, height of CG, length of CG, and OFD were measured as 1.77 ± 0.59 mm, 5.10 ± 1.70 mm, 12.32 ± 2.25 mm, and 1.56 ± 0.56 mm, respectively. No significant difference was observed between the measurements in terms of sex and side ( P > 0.05). Apart from OFD, the parameters were greater in the third-trimester fetuses than in the second-trimester fetuses ( P < 0.001). Olfactory fossa depth was similar in both trimester fetuses ( P = 0.798). Olfactory fossa depth did not alter with advancing gestational weeks ( P = 0.077), but the others increased ( P < 0.01). Only one configuration regarding Keros types was observed. Type 1 was detected in all fetuses (100%). A linear function was calculated as y=1.442+0.455×age for the length of CG, y=-2.566+0.321×age for the height of CG, y=0.641+0.039×age for OFD, and y=-1.088+0.119×age for the width of CG., Conclusions: Crista galli size increased with advancing fetal weeks. The authors detected Keros type 1 in all fetuses. The authors' linear functions representing the growth pattern of CG and OFD in fetuses may be useful in estimating their dimensions., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Congenital meningoencephaloceles of the anterior skull base (ASB) are rare lesions that become evident during childhood and, if not properly diagnosed and treated, can be associated with severe complications. In the past, encephaloceles were treated exclusively with open surgical approaches, which, however, are associated with high complication rates. Recent years have seen the large-scale introduction of transnasal endoscopic approaches to the skull base, and several Authors suggest that endoscopic resection and repair in cases of meningoencephalocele may be the treatment of first choice, being associated with lower complication rates and reduced operative time compared with open procedures. We illustrate step-by-step the transnasal endoscopic treatment of congenital meningoencephalocele and repair of ASB defect by multilayer technique., Competing Interests: Declaration of competing interest The present authors have no financial relationship to disclose. All of the authors have read and approved the manuscript., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Chondrosarcoma of the skull base is a malignant tumor of cartilage origin. Clinical manifestations are nonspecific, early can be asymptomatic. We report a case of asymptomatic chondrosarcoma of the skull base which is difficult to confirm the diagnosis. The patient underwent Type A resection of chondrosarcoma of the skull base through the left subtemporal fossa approach, with postoperative radiotherapy. And the patient achieved good postoperative recovery. Therefore, chondrosarcoma of the skull base is a rare malignant tumor with slow growth. Early detection, excision, and postoperative radiotherapy can achieve a good therapeutic effect., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Skull base surgery requires anatomical knowledge and appropriate surgical technique in bone drilling. We developed a newly modified three-dimensional (3D) model of the posterior cranial fossa as a learning tool that improves knowledge of skull base anatomy and surgical approaches, including skull base drilling techniques., Methods: This bone model of the posterior cranial fossa was created based on computed tomography data using a 3D printer, and incorporates artificial cranial nerves, cerebral vessels, bony structures, dura mater, and cerebellar tentorial dura. These anatomical components are differentiated with various colors. In addition, the atlanto-occipital junction can be mobilized to fully expose the surface of the cartilage between the C1 condyle and occipital condyle to allow drilling to open the hypoglossal canal under a wide surgical field. The usefulness of the model for practicing skull base surgical approaches was evaluated., Results: Experience of bone drilling, dural dissection, and 3D positioning of important structures, including cranial nerves and blood vessels, was identical to that in actual surgery., Conclusions: This model is designed to facilitate teaching anatomical knowledge and essential epidural procedure-related skills, and is useful for teaching the essential elements of posterior skull base surgery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: The posterior maxilla and skull base is a region with a complex anatomy. Accurate resection of the pterygoid plate is critical during a maxillectomy procedure. However, there is a paucity of functional and anatomical studies on the pterygoid plate and skull base. This study aimed to investigate functional anatomy of the pterygoid plate and its surrounding structures in the posterior maxilla to provide a better understanding of surgical procedures in this region., Methods: 3D software was used to measure 3D distances, angles, and areas of key anatomical landmarks on CT images of 100 hemifaces. Morphological classification of pterygoid plates was then performed., Results: Results of comparing right and left pterygoid plates revealed no significant differences in dimensions or angles. Comparisons between sexes revealed that a few parameters were significantly different (P < 0.01), including pterygoid height on the left side, distance from the zygomatico-maxillary buttress to the infraorbital fissure (Zy-IOF), and area of the left lateral pterygoid plate. The morphology of the lateral pterygoid plate was classified into four types based on the shape of the middle region: middle convex (42%), double concave (36%), flattened (10%), and middle concave (12%). The morphology of pterygoid plates was classified based on the divergence of medial and lateral pterygoid plates, with the narrow type (56%) being more common than the wide type in this study cohort., Conclusions: This 3D digital anatomical study measured key landmarks for maxillary resection. Such measurement has never been reported. This anatomical study provides surgeons with information on the anatomy of the posterior maxilla and allows for safer and more accurate resection of the difficult-to-resect posterior maxilla., Competing Interests: Declarations. Ethics approval and consent to participate: This retrospective study was exempted from approval by the Institutional Review Board (IRB) of Seoul National University Dental Hospital (SNUDH) (IRB number: ERI22002). The requirement for informed consent was waived due to the retrospective nature of the study. All methods were performed in accordance with the relevant guidelines and regulations. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: Skull base features, including increased foramen ovale (FO) cross-sectional area, are associated with lateral skull base spontaneous cerebrospinal fluid (sCSF) leak and encephalocele. Manual measurement requires skill in interpreting imaging studies and is time consuming. The goal of this study was to develop a fully automated deep learning method for FO segmentation and to determine the predictive value in identifying patients with sCSF leak or encephalocele., Methods: A retrospective cohort study at a tertiary care academic hospital of 34 adults with lateral skull base sCSF leak or encephalocele were compared with 815 control patients from 2013-2021. A convolutional neural network (CNN) was constructed for image segmentation of axial computed tomography (CT) studies. Predicted FO segmentations were compared to manual segmentations, and receiver operating characteristic (ROC) curves were constructed., Results: 295 CTs were used for training and validation of the CNN. A separate dataset of 554 control CTs was matched 5:1 on age and sex with the sCSF leak/encephalocele group. The mean Dice score was 0.81. The sCSF leak/encephalocele group had greater mean (SD) FO cross-sectional area compared to the control group, 29.0 (7.7) mm 2 versus 24.3 (7.6) mm 2 (P = .002, 95% confidence interval 0.02-0.08). The area under the ROC curve was 0.69., Conclusion: CNNs can be used to segment the cross-sectional area of the FO accurately and efficiently. Used together with other predictors, this method could be used as part of a clinical tool to predict the risk of sCSF leak or encephalocele., Competing Interests: Declarations. Conflict of interests: The authors have no relevant financial or non-financial interests to disclose. Ethics approval: This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of the University of Nebraska Medical Center (June 5, 2019/IRB# 412–19-EX). Informed consent: Informed consent was waived by the IRB due to the retrospective study design without publication of individually identifiable data., (© 2024. CARS.)

Background: The emergence of zero echo time (ZTE) imaging has transformed bone imaging, overcoming historical limitations in capturing detailed bone structures. By minimizing the time gap between radiofrequency excitation and data acquisition, ZTE generates CT-like images. While ZTE has shown promise in various applications, its potential in assessing skull base and calvarium lesions remains unexplored. Hence we aim to introduce a novel perspective by investigating the utility of inverted ZTE images (iZTE) and pseudoCT (pCT) images for studying lesions in the skull base and calvarium., Materials and Methods: A total of 35 eligible patients, with an average age of 42 years and a male/female ratio of 1:4, underwent ZTE MRI and images are processed to generate iZTE and pCT images were generated through a series of steps including intensity equalization, thresholding, and deep learning-based pCT generation. These images were then compared to CT scans using a rating scale; inter-rater kappa coefficient evaluated observer consensus while statistical metrics like sensitivity and specificity assessed their performance in capturing bone-related characteristics., Results: The study revealed excellent interobserver agreement for lesion assessment using both pCT and iZTE imaging modalities, with kappa coefficient of 0.91 (P < 0.0001) and 0.92 respectively (P < 0.0001). Also, pCT and iZTE accurately predicted various lesion characteristics with sensitivity ranging from 84.3% to 95.1% and 82.6%-94.2% (95% CI) with a diagnostic accuracy of 95.56% and 94.44% respectively. Although both of them encountered challenges with ground glassing, hyperostosis, and intralesional bony fragments, they showed good performance in other bony lesion assessments., Conclusions: The pilot study suggests strong potential for integrating the ZTE imaging into standard care for skull base and calvarial bony lesions assessment. Additionally, larger-scale studies are needed for comprehensive assessment of its efficacy., (Copyright © 2024 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

The lateral recess of a well-pneumatized sphenoid sinus is challenging to access surgically. Traditional methods require the use of multiple angled endoscopes and curved instruments which may limit visualization. We describe a prelacrimal-transpterygoid/maxillary approach which offers direct access to this region with a 0° endoscope. Laryngoscope, 134:4918-4922, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Preoperative severity of unicoronal synostosis varies greatly and involves the frontal bone, skull base and orbits. Degree of deformity affects long-term morphological and functional outcomes after surgery. The aim of this study was to describe the morphological heterogenicity and investigate its relation to patient-specific factors., Materials and Methods: In this retrospective cohort study, non-syndromic unicoronal synostosis patients treated between 2006 and 2022 at Necker Hospital, France or Uppsala University Hospital, Sweden, were included and matched to controls. Severity of skull base, orbital and posterior skull asymmetry, degree of anterior plagiocephaly and Harlequin deformity, lateralisation, head circumference, age, timing of metopic fusion and fusion of peri-pterionic sutures were investigated., Results: Ninety-five patients and ninety-three controls were included. Skull base asymmetry was linearly related to orbital asymmetry (p < 0.001), correlated with earlier CT scans (p = 0.004) and anterior (p < 0.001) and posterior (p = 0.03) plagiocephaly. Posterior plagiocephaly was more common in patients (31%) compared with controls (5%) (p < 0.001). A patent metopic suture above nine months of age was associated with severe Harlequin deformity (p = 0.04) and a lower head circumference when fused (p = 0.03). Fronto-sphenoidal suture fusion was associated with later CT scans (p < 0.001) and less skull base asymmetry (p = 0.002). Spheno-parietal fusion was correlated with decreased skull base asymmetry (p = 0.03). Right lateralisation was more common in females., Conclusions: Heterogenicity of unicoronal synostosis seems to be predominantly explained by variability in skull base morphology. Peri-pterionic fusions might limit deformity., (Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

In skull base surgery, the method of using a probe to draw or 3D scanners to acquire intraoperative facial point clouds for spatial registration presents several issues. Manual manipulation results in inefficiency and poor consistency. Traditional registration algorithms based on point clouds are highly dependent on the initial pose. The complexity of registration algorithms can also extend the required time. To address these issues, we used an RGB-D camera to capture real-time facial point clouds during surgery. The initial registration of the 3D model reconstructed from preoperative CT/MR images and the point cloud collected during surgery is accomplished through corresponding facial landmarks. The facial point clouds collected intraoperatively often contain rotations caused by the free-angle camera. Benefit from the close spatial geometric relationship between head pose and facial landmarks coordinates, we propose a facial landmarks localization network assisted by estimating head pose. The shared representation head pose estimation module boosts network performance by enhancing its perception of global facial features. The proposed network facilitates the localization of landmark points in both preoperative and intraoperative point clouds, enabling rapid automatic registration. A free-view human facial landmarks dataset called 3D-FVL was synthesized from clinical CT images for training. The proposed network achieves leading localization accuracy and robustness on two public datasets and the 3D-FVL. In clinical experiments, using the Artec Eva scanner, the trained network achieved a concurrent reduction in average registration time to 0.28 s, with an average registration error of 2.33 mm. The proposed method significantly reduced registration time, while meeting clinical accuracy requirements for surgical navigation. Our research will help to improving the efficiency and quality of skull base surgery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)

Objective: Apparent diffusion coefficient (ADC) value helps in differentiating infections from neoplasms on magnetic resonance imaging (MRI). We investigate the diffusion-weighted images in skull base osteomyelitis (SBO) to evaluate if ADC values can differentiate fungal and bacterial SBO and to analyse the microbiology of all SBO patients., Design: Retrospective observational study., Setting: Quaternary care referral centre., Participants: A retrospective review of 142 patients diagnosed and treated for SBO patients from January 2010 to May 2023 was done., Main Outcome Measure: Chi-square or Fisher's exact test was used to compare ADC values of bacterial and fungal SBO., Results: The most common pathogens isolated were Pseudomonas (42.2%), Aspergillus (30.98%), and S. aureus (23.94%). The average ADC value of affected soft tissues among patients was 1.13 ± 0.26 × 10 -3  mm2/s compared to the average ADC value of normal soft tissue, 1.34 ± 0.31 × 10 -3  mm2/s. There was no statistical significance when comparing the average ADC values of bacterial and fungal SBO patients (p value = 0.142)., Conclusion: This study suggests that though infection due to Pseudomonas was the commonest, it was detected only in 42.2% of patients. More than half of the cases had organisms other than Pseudomonas, demanding the clinician to obtain deeper biopsies early in the course of the disease for microbiological analysis. DWI does not help differentiate bacterial and fungal SBO, again emphasising the need for deeper tissue biopsies in all these patients to assist in the early identification of the pathogen., (© 2024 John Wiley & Sons Ltd.)

Purpose: Anatomical 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., 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., Competing Interests: Declarations. Ethical approval: The Local Institutional Human Ethics Committee approved this retrospective study and waived the need for informed consent (IRB23-021). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

This study investigates the utility of 18 F-sodium fluoride ( 18 F-NaF) positron emission tomography/computed tomography (PET/CT) in assessing skull-base bone invasion (SBBI) and predicting treatment response in advanced nasopharyngeal carcinoma (NPC). A retrospective analysis was conducted on 142 patients with newly diagnosed advanced NPC who underwent 18 F-NaF PET/CT for initial staging from December 2020 to December 2023. 18 F-NaF PET/CT scans were analyzed for uptake values at the skull-base bone, and these were correlated with treatment outcomes of primary tumor using the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Statistical analyses involved Mann-Whitney U tests for group comparisons and logistic regression for evaluating risk factors. Higher 18 F-NaF uptake at the skull-base bone was significantly associated with advanced T stages (p < 0.0001) and the presence of bone metastases (p = 0.01). Patients exhibiting complete response (CR) to treatment had significantly lower skull-base 18 F-NaF uptake compared to those with non-CR (p < 0.001). Receiver operating characteristic (ROC) analysis identified an SUV max  > 10.0 and SUV mean  > 5.2 as predictive of non-CR, with AUC values of 0.77 and 0.76, respectively. Univariate and multivariable analysis confirmed SUV max as a significant predictor of treatment response (OR = 7.03, 95% CI: 1.97-25.13, p < 0.05). Elevated 18 F-NaF uptake at the skull-base bone is predictive of poorer treatment outcomes, highlighting its potential as a prognostic biomarker in advanced NPC. This study demonstrates that 18 F-NaF PET/CT is a valuable imaging modality for evaluating SBBI in NPC, offering metabolic information that complements the anatomical findings from MRI., Competing Interests: Competing interests: The authors declare no competing interests. Ethical approval and consent to participate: This retrospective study received ethical clearance and the requirement to obtain informed consent was waived by the institutional review boards of Affiliated Hospital of Guilin Medical University (ID: 2023QTLL-16). The study protocol adheres to the tenets of the 1964 Declaration of Helsinki., (© 2024. The Author(s).)

Objective: The selection of appropriate materials and techniques for reconstructing skull base defects is crucial for restoring function, minimizing complications, and enhancing aesthetics. Dermal fat grafts (DFGs) have been established in many surgeries for contour correction. However, there is little literature describing the application of free dermal fat grafts for reconstruction of lateral skull base surgery defects. Therefore, the aim of this study was to evaluate the clinical effect of using free dermal fat grafts in the reconstruction of lateral skull base defects., Methods: In this study, 32 patients who underwent primary autologous free dermal fat graft reconstruction for lateral skull base defects were enrolled. Postoperative complications both in the donor and recipient area were evaluated. Three-dimensional (3D) reconstruction techniques were applied to visualize the fat graft shape and volume variations for the assessment of postoperative restoring function. A telephone questionnaire was used for the assessment of postoperative facial aesthetics and patient satisfaction., Results: A total of 32 patients who met the inclusion criteria were included in the study, showing satisfying results in safety and aesthetics. Participants' ages averaged at 42.03 years, with the youngest being 18 and the oldest at 75 years old. No patient had postoperative complications of abdominal wounds in the donor area, only two patients had postoperative infections and one patient had a postoperative effusion in the recipient area. The volume of the grafts ranged from a minimum of 24.4 cm³ to a maximum of 131 cm³, with the highest recorded resorption volume being 33.63 cm³. The average resorption rate of the dermal fat graft was 24.36%, ranging from a minimum of 11% to a maximum of 43%. 3D reconstruction based on MRI imaging data indicated that DFGs have a lower resorption rate than traditional free fat grafts. The telephone questionnaire revealed high patient satisfaction with facial aesthetics, with the majority rating their outcomes positively., Conclusions: Dermal fat grafts have fewer complication and can provide better resistance to infection and radiation aspect. Based on 3D reconstruction techniques via MRI imaging data, we found that dermal fat grafts have lower resorption rate than traditional free fat grafts, which can be a suitable material for reconstruction of lateral skull base defects., (© 2024. The Author(s).)

This study aimed to investigate sex differences in craniomaxillofacial parameters in children and adolescents. Lateral cephalograms were obtained from 340 subjects (141 male, 199 female) aged 6 to 18 years, and their craniofacial characteristics and cervical vertebral maturity were assessed using the quantitative cervical vertebral maturity (QCVM) method. Age-based stratified analyses on craniofacial parameters and further comparison in QCVM Ⅲ subjects were performed. Among all analyses, male subjects had significantly greater value than females in sex-different parameters except for facial convexity. The overall group had 17 sex-different parameters (ramus height, anterior facial height (AFH), posterior facial height (PFH), upper anterior facial height (UAFH), lower anterior facial height (LAFH), anterior cranial base length, posterior cranial base length, facial convexity, upper lip length, upper lip thickness, lower lip thickness, soft tissue chin thickness, nasion of soft tissue-subnasale (N'-Sn), subnasale-menton of soft tissue (Sn-Me'), subnasale-stomion inferius (Sn-Sto)). The <12 years old group showed 6 significant sex differences (AFH, LAFH, lower lip protrusion, lower lip thickness, N'-Sn, Sn-Me'). While the ≥12 years old group occurred two more parameters (mandibular body length, AFH/PFH) than the overall group. 12 cephalometric parameters had significant sex differences among QCMV III patients. After age adjustment, the number of sex-different parameters only increased in soft tissue. Craniofacial characteristics and cervical vertebrae maturation of the youngsters exhibited significant sex differences. Though females reached an earlier cervical vertebral maturation, they still had smaller craniofacial linear features. Sex differences should be taken into account in developing reference standards for cephalometric measurements and treatment planning in the clinic., Competing Interests: The authors declare no conflict of interest., (©2024 The Author(s). Published by MRE Press.)

Introduction: Endoscopic approaches for skull base pathologies are increasingly being performed, and the subsequent complications, especially in the long term, have also been partially clarified. However, there is no information on the effects of endoscopic endonasal skull base surgeries (EESBS) in children on odor and facial development in parallel with long-term development. We conducted this study to investigate postoperative olfactory function and facial development in pediatric patients who underwent skull base surgery using the endoscopic endonasal method., Methods: We evaluated the smell test, sinonasal symptoms, and facial development of pediatric patients who underwent endoscopic endonasal skull base surgery after long-term follow-up. Odor was evaluated using the "Sniffin' Sticks" test kit, which assessed the T (odor threshold), D (odor discrimination), and I (odor identification) parameters. Sinonasal symptoms were evaluated using the SNOT-22 (sinus-nose outcome test) questionnaire. SNA (sella-nasion-A point), SNB (sella-nasion-B point), and ANB (A point-nasion-B point) angles were calculated from maxillofacial tomography and magnetic resonance imaging) to evaluate facial development. Data were compared with those of the healthy control group., Results: We included 30 patients comprising 19 (63.3%) boys and 11 (36.7%) girls, with no age difference between case and control groups. The mean follow-up period was 7 years. Odor test data, cephalometric measurements, and SNOT-22 analysis results showed no statistically significant differences between the two groups., Conclusion: To our knowledge, this is a comprehensive study with the longest follow-up period in terms of evaluation of facial development after EESBS in children to analyze odor using the Sniffin' Sticks test kit and the quality of life using SNOT-22. Olfactory function, facial development, and quality of life remained unaffected after long-term follow-up after EESBS  in children. Although this surgical approach is minimally invasive, we recommend considering the possibility of complications, and the procedure should be performed by an experienced surgical team with adequate equipment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The most used neurosurgical approach to reach cerebellar-pontine angle is the retrosigmoid route. This article describes the presigmoid approach which requires excellent knowledge of the labyrinthine block together with quantitative analysis of temporal bone CT., Methods: CT-based quantitative measurements were obtained in patients undergoing vestibular neurectomy with a presigmoid approach. Eighteen patients were enrolled, and five measures were taken: Trautmann's area, the petro-clival angle, presigmoid dura length and its angle. The relationship between these measurements and hospitalization days, operating times, and complications was explored., Results: The posterior semicircilar canal (PSC)-sigmoid sinus (SS) distance, presigmoid dura- internal auditory canal (IAC)-PSC angle, and duration of surgery are predictors of complications. Specifically, a PSC-sigmoid sinus distance <11 mm, a dura presig-IAC-PSC angle <14 are associated with the highest risk of complications., Conclusion: Preoperative temporal bone CT scan can guide the surgeon through the narrowest areas of the surgical approach. Trautmann's triangle area and petro-clival angle reduction are challenging and can be faced with combined microscopic-endoscopic technique, and with optics angulation-rotation. The retrolabyrinthine approach can enable hearing preservation and minimal cerebellar retraction., (Copyright © 2024. Published by Elsevier España, S.L.U.)

Objective: The short T2 nature of cortical bone causes it to appear similar to air on MR, forcing clinicians to rely on computed tomography imaging, with its attendant ionizing radiation exposure, to define temporal bone structures. Through the use of novel MR sequences with ultra-short echo times (UTE), short T2 structures are now able to be visualized, allowing for improved understanding of anatomical relationships., Methods: Eight patients (50% female) undergoing MR imaging of the skull base for diagnostic purposes (62.5% for vestibular schwannoma surveillance) at a tertiary care center were enrolled to evaluate the safety and efficacy of UTE imaging. CT scans were completed in 37.5% of the patients as part of their workup and used for comparison purposes. The repetition time, short echo time, and long echo time for the UTE sequence were 11, 0.032, and 2.2 msec, respectively., Results: The protocol added 6 min to the total scanning time, and all patients tolerated the sequence without issue. The ossicles, mastoid air cells, antrum, and epitympanum were able to be seen and had a high Dice similarity coefficient when compared to CT (>0.5). UTE allowed for clear delineation of all segments of the facial nerve with a signal-to-noise ratio of 35 (although the BRAVO sequences had a superior ratio of 140). Vestibular schwannomas were able to be distinguished from normal brain parenchyma., Conclusions: UTE is safe and effective for visualizing anatomic structures not normally seen on traditional MRI, potentially allowing for improved surgical planning in patients., Level of Evidence: 3 Laryngoscope, 134:4691-4696, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

This study combined qualitative and quantitative approaches to evaluate outcomes of isolated nonsyndromic unilateral lambdoid synostosis at the Children's Hospital of Philadelphia. Volumetric, linear, and angular analyses were performed on long-term postoperative and normal control scans. Preoperative and postoperative clinical photographs were evaluated for the presence of dysmorphic frontofacial features. Among 26 included patients, median age of surgery was 10 months and mean postoperative follow-up was 5.9 ± 5.7 years. Two (7.7%) patients underwent secondary cranial vault procedures. At most recent follow-up, 2 (7.7%) subjects reported intermittent headaches. Twenty (90.9%) of 22 patients were assigned Whitaker grade I. Among 9 subjects with long-term imaging at age 11.5 ± 5.3, posterior vault asymmetry, posterior fossa deflection angle, cranial base angle, and ear position asymmetry all remained greater than in the control group. Of subjects included in the frontofacial feature analysis (n = 10), 50% had resolution of all dysmorphic frontofacial features present preoperatively. Overall, most subjects who underwent PVR did not require revisional surgery and had good outcomes both aesthetically and functionally. Despite residual abnormalities in the cranial base and posterior vault, most had resolution of parietal bossing and facial scoliosis. Ear position asymmetry was the most common dysmorphic feature at long-term follow-up., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: To evaluate the effect of the basilar invagination (BI) type B on cervical spine., Methods: The research protocol used head magnetic resonance imaging (MRI) exams from 41 participants with BI type B and 158 controls. The criterion for BI was the distance of the odontoid apex to Chamberlain's line (DOCL) equal to or greater than 7 mm. The clivus length (CLI), clivus canal angle (CCA), Welcker's basal angle (WBA), Boogaard's angle (BOA), upper cervical lordosis angle (UCL), and total cervical lordosis angle (CL) were evaluated. The descriptive analysis, group comparisons, and correlations between skull base and cervical spine parameters were performed at the 95% CI., Results: Participants with BI type B showed shorter clivus length (CLI: 25.7 ± 7.3 mm); greater angulation of the skull base (WBA: 126.5 ± 10.4); greater inclination foramen magnum (BOA: 151.5 ± 14.5); decrease in the value of the CCA (131.6 ± 15); and greater angulations of UCL (17.9 ± 13.8) and CL (29.7 ± 19.9) in comparison to the control group (P < 0.05). Clivus length and CCA correlated inversely with UCL and CL, while BOA correlated directly with UCL and CL. The WBA did not correlate with CL (P < 0.05)., Conclusions: The deformation of skull base in the BI of type B caused, on average, a hyperlordosis of almost 30° in the C2-C6 segment. This change was approximately 17° in the C2-C4, with the clivus hypoplasia being a risk factor for cervical hyperlordosis., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The skull base is a complex region in neurosurgery, featuring numerous foramina. Accurate identification of these foramina is imperative to avoid intraoperative complications and to facilitate educational progress in neurosurgical trainees. The intricate landscape of the skull base often challenges both clinicians and learners, necessitating innovative identification solutions. We aimed to develop a computer vision model that automates the identification and labeling of the skull base foramina from various image formats, enhancing surgical planning and educational outcomes., Methods: We employed a deep learning methodology, specifically using a convolutional neural network architecture. Our model was trained on a dataset comprising of 3560 high-resolution, annotated images of the skull base, taken from various perspectives and lighting conditions to ensure model generalizability. Model performance was quantitatively assessed using precision and recall metrics., Results: The convolutional neural network model demonstrated strong performance, achieving an average precision of 0.77. At a confidence threshold of 0.28, the model reached an optimal precision of 90.4% and a recall of 89.6%. Validation on an independent test set of images corroborated the model's capability to consistently and accurately identify and label multiple skull base foramina across diverse imaging scenarios., Conclusions: This study successfully introduces a highly accurate computer vision model tailored for the identification of skull base foramina, illustrating the model's potential as a transformative tool in anatomical education and intraoperative structure visualization. The findings suggest promising avenues for future research into automated anatomical recognition models, suggesting a trajectory toward increasingly sophisticated aids in neurosurgical operations and education., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: This study aims to investigate the anatomical features relating to nasofrontal and septum osteotomy during Le Fort Ⅲ osteotomy among patients with syndromic craniosynostosis, and to compare them with normal controls using computed tomographic cephalometry., Materials and Methods: A total of 63 subjects were included (syndromic craniosynostosis, n = 21; controls, n = 42). The craniosynostosis subjects were subdivided into group A (craniosynostosis patients without history of previous surgery, n = 8) and group B (craniosynostosis patients with history of previous surgery, n = 13). Cephalometric measurements based on computed tomographic images were analyzed., Results: The angle between the refencing plane (HP) of the anterior cranial base and the most inferior point of the sphenoid sinus via Nasion (∠HP-N-ISS) was 23.85 ± 3.10°, 21.15 ± 4.64° and 28.32 ± 2.92° for group A, group B and the control group, respectively. The angle between HP and the posterior nasal spine (PNS) via nasion (∠HP- N- PNS) was 42.63 ± 2.02°, 38.50 ± 4.84° and 47.68 ± 2.62° for group A, group B and the control group, respectively., Conclusion: This study characterized the surgically relevant anatomical features in nasofrontal osteotomy during Le Fort Ⅲ osteotomy. The safe range for osteotomy angle is significantly different between normal and syndromic craniosynostosis subjects. Awareness of this difference may prevent further complications., Competing Interests: Declaration of competing interest The authors declare no conflict of interests., (Copyright © 2024. Published by Elsevier Ltd.)

Background and Objectives: Brainstem cavernous malformations (BCMs) are a distinct clinical entity that carry a high risk of patient morbidity because of location and risk of hemorrhage. Surgical management of these lesions requires intimate knowledge of surgical anatomy and skull base approaches. This article is intended to highlight a modern approach for the treatment of BCMs, with an emphasis on the use of the one-point technique to guide resection., Methods: We describe a case series of BCMs treated through a variety of skull base approaches, describing our decision-making strategy. We review the concept of the one-point technique focusing on the safest access to the malformation through 2 representative cases and also perform a retrospective review of 32 consecutive patients who underwent BCM resection to present outcomes and the comparison of two-point vs one-point techniques., Results: Consecutive series of 32 patients in whom the one-point technique was used is presented. In 8 patients (25%), the traditional two-point technique would suggest a different trajectory than the one-point technique. Postoperative MRI confirmed complete resection in 30 patients (95%), and 29 patients (91%) had modified Rankin Scale (0-2) at follow-up. All patients in whom the one-point technique guided a different trajectory had gross total removal of the cavernous malformation, with one patient having long-term new neurological impairment from the surgery. There were no mortalities., Conclusion: Despite surgical advances in recent decades and more widespread understanding of surgical anatomy and safe entry zones, surgical resection of BCMs remains a formidable challenge. While not necessarily the shortest access, the one-point technique offers a safe approach considering all the different modalities in our armamentarium and can be used as part of a strategy to determine the optimal approach to resect BCMs., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Purpose: This study assesses the reliability of deep learning models based on planar whole-body bone scintigraphy for diagnosing Skull base invasion (SBI) in nasopharyngeal carcinoma (NPC) patients., Methods: In this multicenter study, a deep learning model was developed using data from one center with a 7:3 allocation to training and internal test sets, to diagnose SBI in patients newly diagnosed with NPC using planar whole-body bone scintigraphy. Patients were diagnosed based on a composite reference standard incorporating radiologic and follow-up data. Ten different convolutional neural network (CNN) models were applied to both whole-image and partial-image input modes to determine the optimal model for each analysis. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration, decision curve analysis (DCA), and compared with expert assessments by two nuclear medicine physicians., Results: The best-performing model using partial-body input achieved AUCs of 0.80 (95% CI: 0.73, 0.86) in the internal test set, 0.84 (95% CI: 0.77, 0.91) in the external cohort, and 0.78 (95% CI: 0.73, 0.83) in the treatment test cohort. Calibration curves and DCA confirmed the models' excellent discrimination, calibration, and potential clinical utility across internal and external datasets. The AUCs of both nuclear medicine physicians were lower than those of the best-performing deep learning model in external test set (AUC: 0.75 vs. 0.77 vs. 0.84)., Conclusion: Deep learning models utilizing partial-body input from planar whole-body bone scintigraphy demonstrate high discriminatory power for diagnosing SBI in NPC patients, surpassing experienced nuclear medicine physicians., (© 2024. The Author(s).)

Background and Purpose: CSF leaks of the skull base and spine share a common process of CSF volume loss, and yet only the latter has been associated with spontaneous intracranial hypotension (SIH). Despite published claims that only spinal leaks cause SIH, no prior studies have evaluated brain MR imaging in patients with skull base leaks for findings associated with SIH, such as dural enhancement. The purpose of our study was to use a validated brain MR imaging scoring system to evaluate patients with skull base CSF leaks for findings associated with SIH., Materials and Methods: We included patients with confirmed skull base CSF leaks and contrast-enhanced preoperative brain MRI. The preoperative MR images were reviewed for findings associated with SIH by using the Bern score. Patient age, presenting symptoms and their duration, and leak site were also recorded., Results: Thirty-one patients with skull base CSF leaks were included. Mean Bern score was 0.9 (range 0-4, standard deviation 1.1), and only 1 patient (3%) had dural enhancement. Mean age was 53 years (range 18-76). Mean symptom duration was 1.3 years, with 22 patients presenting within 1 year of symptom onset. Twenty-three patients (74.2%) had intraoperative confirmation of leak from the middle cranial fossa, involving the temporal bone, while 7 (22.6%) had leaks from the anterior skull base. One patient, who had dural enhancement, had an infratentorial CSF leak along the petrous segment of the internal carotid artery., Conclusions: Our study provides further evidence that skull base and spinal CSF leaks represent distinct pathophysiologies and present with different brain MRI findings., (© 2024 by American Journal of Neuroradiology.)

Background and Objectives: Anterior basal encephaloceles are considered a rare entity and are often associated with midline cerebral abnormalities. Those with a large skull base defect and herniation of brain parenchyma in the neonate or young infant present unique challenges for surgical management., Methods: We analyzed the neurosurgical administrative and operative databases between 1986 and 2022 to determine clinical presentation, operative approach, and outcome of basal encephaloceles., Results: Over the 36-year period, 27 pediatric anterior basal encephaloceles were managed, of which 22 had full documentation and images allowing comprehensive review. Mean age at presentation was 5 years (SD 4.94). The majority were transethmoidal encephaloceles (59%), followed by the transsphenoidal-sphenoethmoidal type (32%). Overall, 91% were managed surgically by a transcranial, endoscopic, or combined approach. Four children required subsequent procedures, predominantly for persistent cerebrospinal fluid leak. No significant differences in proportion of patients requiring interval/revision surgery after initial conservative, endoscopic endonasal, or transcranial surgery was identified. Neither age at surgery nor size of the defect on computed tomography scan was associated with the need for revision surgery. Size of cranial defect was significantly smaller in the endoscopic group ( P = .01). There was a historic tendency for younger children with larger defects to have a transcranial approach. With the addition of endoscopic skull base expertise, smaller defects in older children were more recently treated endoscopically., Conclusion: Basal encephaloceles are rare and complex lesions and are optimally managed within a skull base multidisciplinary team able to provide multiple approaches. Large skull base defects with brain parenchymal involvement often require a transcranial or combined transcranial-endoscopic approach., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

We report a case of upper parapharyngeal abscess arising from progression of a central skull base osteomyelitis, in a patient with poorly controlled diabetes mellitus. Our case is unusual for its presentation in an upper parapharyngeal location, involvement of the skull base, and poor response to medical treatment, hence requiring transnasal endoscopic surgical drainage to achieve definitive treatment. Here, we share our experience with a safe and effective technique of transnasal endoscopic drainage of a parapharyngeal abscess. Laryngoscope, 134:4274-4277, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

Objective: In this study, the authors assessed an algorithm for the diagnosis and management of idiopathic intracranial hypertension (IIH) in patients who had undergone surgical repair of skull base meningoencephaloceles presenting with spontaneous cerebrospinal fluid (sCSF) leakage., Methods: The authors conducted an institutional retrospective review of patients surgically treated for skull base sCSF leaks between 2014 and 2021. Opening pressure (OP) measurements were taken intraoperatively. The algorithm recommended a ventriculoperitoneal shunt (VPS) for high-risk patients (OP ≥ 30 cm H2O), 4 weeks of acetazolamide plus a 2-week washout and repeat lumbar puncture (LP) at 6 weeks for intermediate-risk patients (OP = 20-29 cm H2O), and repeat LP at 4-6 weeks for low-risk patients (OP < 20 cm H2O). Demographics, radiographic characteristics, management adherence, and outcomes were analyzed., Results: Eighty patients with sCSF leakage were identified. The mean age was 51.9 years, and the mean body mass index was 36.3 kg/m2. The median follow-up was 8.3 months (IQR 3.3-19.7 months). The overall VPS rate was 15.0%. Three patients (3.8%) experienced acute recurrent leakage, and 3 (3.8%) developed remote recurrent leaks (mean time of 48.1 months). For the 50 patients with both intra- and postoperative OPs, the mean OPs were not significantly different (23.3 vs 23.0 cm H2O, respectively, p = 0.82). The mean variability between the two measurements was an absolute difference of 6.6 cm H2O. While 13 patients (26.0%) moved to a higher-risk category based on postoperative OP, 18 patients (36.0%) moved to a lower-risk category., Conclusions: Utilizing an algorithm of direct meningoencephalocele repair and selective shunting, acute and remote CSF leak recurrence rates were each 3.8%, and the VPS rate was 15.0%. These data provide further insight into CSF dynamics in this population and argue against the theoretical concern that CSF pressure will increase postrepair. Significant intraindividual variability suggests multiple LPs may be necessary before committing to invasive IIH treatment. Further work is necessary to determine the optimal IIH management strategy.

Objectives: The objectives of this study were to evaluate the accuracy of morphometry of skull base and palate in gender discrimination using cone beam computed tomography (CBCT) scanning and to assess the accuracy of the results among a sample of the Arab population., Materials & Methods: Using CBCT scans, a cross-sectional analysis was conducted on 142 consented patients who underwent various dental procedures at the University Dental Hospital, Sharjah (UDHS). Of these patients, 70 were females and 72 were males, with respective means of 38.5 and 36.2 years. Eleven parameters related to skull base and palatal region were measured on the CBCT scans by two expert radiologists followed by statistical analysis., Results: There was significant gender-based difference in the mean palatal width (PW) ( p  = 0.001), mean palatal height (PH) ( p  = 0.005). Among other skull base region parameters that were significant in term of gender-based difference like; the clivus length (CL) ( p  < 0.001), occipital condyle height (OCH) ( p  < 0.001), basal angle (BA) ( p  = 0.006) and transverse diameter of foramen magnum ( p  = 0.003). Only palate variables showed a significant age difference. Discriminant analysis related to gender showed that occipital condyle height was the most accurate and best discriminator among the skull base region parameters., Conclusion: The use of discriminant analysis in CBCT based on skull base and palatal region variables provides an efficient method for determining gender, which is particularly valuable in forensic science and anthropological research., Significance of Study: Accurate gender identification is crucial in forensic investigations, and the skull base region, being a stable and sexually dimorphic anatomical feature, can serve as a reliable marker for this purpose., Competing Interests: The authors declare there are no competing interests., (©2024 Uthman et al.)

Background: Encephalocele refers to protrusion of the meninges and brain tissue through a skull bone defect. It results from congenital, traumatic, neoplastic, or spontaneous reasons. Traumatic encephalocele occurs because of the posttraumatic fracture of the skull bone or iatrogenic causes. The manifestations vary a lot, such as rhinorrhea, seizures, headaches, and focal neurological deficits., Case Presentation: A 20-year-old Syrian male presented to our department with the complaint of clear cerebrospinal fluid drainage from his right nostril, which started 6 years ago after a head trauma, moderate headache, and episodes of tonic-clonic seizures without any response to medical treatment. Then, 2 months ago, the patient had meningoencephalitis, so he was admitted to the intensive care unit and treated for a month until he was cured. The patient underwent radiological investigations, which showed that he had a base fracture with an encephalocele in the nasal cavity. The brain tissues with the meninges herniated through the skull base fracture with a significant expansion of the subarachnoid spaces in the right hemisphere. He was advised to undergo surgical repair at that time, but he refused the surgery. During this visit, surgery was indicated. The surgery was done by a specialist who returned the herniated brain tissues to their normal location, repaired the meninges, and reconstructed the skull base with bone cement and bio-glue. The patient's recovery after the surgery was uneventful., Conclusion: Traumatic encephalocele is a rare and unexpected complication of trauma, but we should keep it in mind when the patient comes with head trauma because of its life-threatening consequences. This complication can happen after years of trauma if the patient refuses treatment, therefore, we must educate patients about the dangerous results of neglecting cerebrospinal fluid leakage and skull fractures., (© 2024. The Author(s).)

Purpose: Cranial base flexure is an overlooked topic in craniofacial research. The aim of this retrospective observational study was to compare a new parameter, the planum clival angle (PCA), which represents cranial base flexure, in skeletal class I, II, and III malocclusions using cone beam computed tomographic images (CBCT) and correlate PCA with the stages of the fusion of the spheno-occipital synchondrosis (SOS)., Materials and Methods: A total of 125 CBCTs were divided into two groups based on chronological age (19-25 years and 12-18 years). The CBCT images from 57 subjects (19-25 years old) were categorized into three groups based on their skeletal malocclusion for measuring PCA and cranial base angles (CBA). In the second group, comprising 68 CBCT data sets of individuals in the age group of 12-18 years, the PCA angle was correlated with stages of fusion of the SOS. Data were statistically analyzed using independent samples t test, one-way analysis of variance (ANOVA, intergroup), Pearson correlation, and χ 2 test., Results: There was a statistically significant linear correlation (P < 0.001) between the two parameters PCA and CBA but no significant difference was found in PCAs between the three groups. One-way ANOVA to compare the PCA values in the three stages of fusion of the SOS revealed a highly significant relationship in male subjects (p < 0.001), thereby, suggesting that as fusion progresses, the planum clival angle increases. The χ 2 test to compare the planum clival angle in males and females revealed that SOS fusion occurred earlier in females., Conclusion: There is a constant dynamic change in the value of the parameter PCA that progresses until completion of SOS fusion. The SOS fuses earlier in females. Assessment of the stage of fusion of the SOS can be used in deciding whether growth modification of the craniofacial complex is still possible during orthodontic therapy., (© 2023. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Cerebrospinal fluid (CSF) leakage is a common complication associated with endoscopic endonasal skull-base surgery (EESBS). Postoperative mobilization-associated postural changes are considered to cause CSF leakage. However, no study has demonstrated a robust relationship between postural changes and CSF leakage. We used upright computed tomography (CT) to clarify the effects of postural changes on the reconstructed skull base (RSB) after EESBS. Thirty patients who underwent EESBS at our institution were prospectively included, and their upright and supine CTs were compared to measure morphological changes in the RSB. Patient clinical data were also collected from medical charts and surgical videos, and their relationships with morphological changes were assessed. In upright CTs, the RSB shifted intracranially by 0.94 (0.0-2.9) mm on average. This shift was larger in cases with lesions extending to the sphenoid sinus, dural defects, intraoperative pulsation of the RSB, and large bone windows. The direction of the change was opposite to intuitive movement driven by gravity because of reduced intracranial pressure in the sitting position. Thus, these shifts can be directly associated with postoperative CSF leakage caused by reconstruction material displacement. Skull-base reconstruction and postoperative postural management accounting for these morphological changes may be necessary for preventing CSF leakage., (© 2024. The Author(s).)

Purpose: The intraoperative detection of cerebrospinal fluid (CSF) leaks during endoscopic skull base surgery is critical to ensure watertight sealed defects. Intrathecal fluorescein (ITF) is a valuable adjunct to intraoperative investigation. Hence, our aim is to summarize the evidence of the efficacy of ITF as an accurate diagnostic modality and reconstruction guide for non-congenital skull base defects., Methods: Using the Cochrane Central, MEDLINE, and Embase databases, we identified studies involving the use of ITF in non-congenital CSF leaks which were published until November 2023. The STATA 18 software was used for meta-analysis., Results: Fourteen studies met the inclusion criteria, in which seven studies were included in the meta-analysis. ITF was used in 1898 (90.3%) of patients, with a detection rate of 88.1%. The overall detection rate of non-congenital CSF leaks among ITF concentrations of 5% and 10% had a statistically significant pooled effect size of 2.6 (95% CI = 2.25, 2.95), while when comparing the ITF to other alternative radiological tests, it was not statistically significant with a mean difference of 0.88 (95% CI = - 0.4, 2.16). Moreover, the pooled prevalence was statistically significant in regards of the complications associated with ITF with an effect size of 0.6 (95% CI = 0.39, 0.82), indicating that 60% of patients who underwent ITF would experience at least one of the measured complications., Conclusion: ITF is considered as an efficient tool in localizing skull base defects. However, there was no significant results when comparing the ITF to other alternative radiological tests. Accordingly, if the ITF intervention is indicated, patients should be carefully selected based on their clinical need., (© 2024. The Author(s).)

Intraoperative imaging during skull-base surgery allows the operator to control surgical dissection and to tailor the approach, reducing morbidity due to inadequate resection or reintervention. The O-arm® (Medtronic, Fridley, MN, USA) navigation system is an intraoperative cone-beam CT device that was first designed for spinal surgery but now has applications in lateral skull-base surgery. In this technical note, we present a patient with petrous apex cholesterol granuloma located medial to the intrapetrous internal carotid artery and in the infralabyrinthine compartment. We report the possibility of natural drainage, using intraoperative imaging to guide resection, through a rapid, safe and minimally invasive approach., (Copyright © 2023. Published by Elsevier Masson SAS.)

Objective: Recurrent cerebrospinal fluid (CSF) rhinorrhea caused by sequential, anatomically separated skull base defects is rarely reported in the literature. Neither management nor etiology has been sufficiently investigated. We present an illustrative case and a systematic review of the literature regarding etiology, diagnostics, and management of this rare phenomenon., Methods: A systematic literature search looking for articles reporting sequential CSF leaks with multiple skull base defects was performed. Data from included articles were descriptively reported, and the quality of the included studies was assessed with Grading of Recommendations Assessment, Development and Evaluation., Results: A 71-year-old woman with posttraumatic CSF rhinorrhea and left-sided CSF otorrhea due to a left-sided horizontal fracture of the petrous bone presented at our institution. After initial surgical repair and a 10-week symptom-free interval, CSF rhinorrhea recurred. Imaging revealed a preexisting contralateral meningoencephalocele of the lateral sphenoid recess causing recurrent CSF rhinorrhea most likely after initial traumatic laceration. The defect was successfully treated. A literature search identified 366 reports, 6 of which were included in the systematic review with a total of 10 cases. Quality was deemed good in 8 of 10 cases. The most common location for primary and sequential CSF leaks was along the sphenoid bone (4/10 and 5/10 patients, respectively). All publications except one reported the presence of a meningo (encephalo)cele as cause of the sequential CSF leak., Conclusions: Occurrence of recurrent CSF rhinorrhea due to an anatomically separated sequential skull base lesion remains a rare phenomenon. Reassessment of imaging studies and a structured diagnostic workup to detect sequential CSF leaks independent of the primary lesion should is recommended., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: The aim of this study was to evaluate artifacts in the skull base region of head computed tomography (CT) images with various tilt angles relative to the orbitomeatal line., Methods: CT images of a head phantom acquired by helical and non-helical scanning with the tilt angles set from 0 to 20 degrees in 5-degree increments were evaluated in this study. Regions of interest (ROIs) were set at the cerebellum, temporal lobe, frontal lobe, and basal ganglia in the phantom images. Artifacts were evaluated by the coefficient of variation (CV) of the mean CT value between ROIs and the location parameter (β) of the Gumbel method., Results: The CV and β values increased with increasing tilt angle for both helical and nonhelical images in the frontal lobes, but both decreased in the cerebellar region. In the temporal lobe and basal ganglia, there was no trend of change with tilt angle., Conclusion: Increasing the tilt angle relative to the OM line increased artifacts at the frontal lobes and decreased artifacts at the cerebellar region.

Cerebrovascular complications from blunt trauma to the skull base, though rare, can lead to potentially devastating outcomes, emphasizing the importance of timely diagnosis and management. Due to the insidious clinical presentation, subtle nature of imaging findings, and complex anatomy of the skull base, diagnosing cerebrovascular injuries and their complications poses considerable challenges. This article offers a comprehensive review of skull base anatomy and pathophysiology pertinent to recognizing cerebrovascular injuries and their complications, up-to-date screening criteria and imaging techniques for assessing these injuries, and a case-based review of the spectrum of cerebrovascular complications arising from skull base trauma. This review will enhance understanding of cerebrovascular injuries and their complications from blunt skull base trauma to facilitate diagnosis and timely treatment., (© 2024. The Author(s).)

Objective: Skull base anatomy around the internal carotid artery (ICA) is extremely complex. Among anatomical landmarks studied, the vidian canal has been thoroughly evaluated, unlike the vidian nerve (VN). Our aim is to evaluate the VN-ICA relationships, and understand their role in terms of surgical planning., Methods: Fifty MRI examinations of 100 healthy petro-spheno-clival regions were reviewed in order to evaluate the relationship between the vidian nerve axis (VNA) and the petrous ICA. Twenty-seven cases of expanded endonasal approaches to petrous apex region were evaluated to check the VN-ICA relationship intraoperatively., Results: MRI evaluations showed that, in 23% of cases, the VNA was below the edge of the ICA, in 45% it was at the edge of the ICA and in 32% it ended up above the edge of the ICA. Surgically speaking, in 9 of 28 petrous apex approaches, the VN ended above the inferior edge of the petrous carotid., Conclusions: MRI evaluation adds useful information in planning the surgical approach to petro-spheno-clival regions, even if the identification of VNA, in these cases, may not be radiologically possible. Surgical experience confirms the importance of VN identification in guiding the surgeon in complex cases, and also outline the possible risks of relying only on this landmark., (Copyright © 2024 Società Italiana di Otorinolaringoiatria e Chirurgia Cervico-Facciale, Rome, Italy.)

Purpose: The topic of osseous variations of the craniocervical junction is a complex morphological and embryological chapter of human anatomy, with a possible impact on neurogical and vascular functionality in this morphological variable region., Material & Methods: An until now undescribed anatomical variation of the exoccipital part of the occipital bone has been observed after maceration at the outer skull base of a West-European 68-year-old male body donor., Results: On both sites of the foramen magnum accessory osseous processes were observed that arise from the jugular process and point towards the lateral margin of the foramen magnum. On the left site this process forms a full arc that bridges the condylar fossa completely., Conclusion: The observed osseous bridge over the condylar fossa has not been reported on before and can be explained by the partial persistence of a primordial vertebra between atlas and occipital bone: the Proatlas. The resulting accessory structure may affect due to its topographic conditions the V3-Segment of the vertebral artery and its accompanying nerves, and thus, play a role in diagnosis and therapy of vascular and/or neurological symptoms of head and neck., (© 2024. The Author(s).)

We describe the extremely unusual case of a childhood injury to the skull base presenting after many years, as a foreign body with chronic granulomatous infection of the brainstem, mimicking neoplasm. TB had an inconsequential penetrating injury to the left cheek, from a bamboo spike aged 15. After 4 years, he developed worsening left sided weakness, imaging at this time was normal. After a car accident aged 40, the weakness worsened further and imaging demonstrated a foreign body entering the skull base. At its tip, it had caused a chronic granulomatous reaction within the brainstem. Surgical removal of this bamboo splinter was via an infratemporal, transzygomatic craniotomy and TB made a good recovery postoperatively. This unusual case demonstrates the important of close inspection of imaging, and thorough history taking. It also questions the chronology of the ossification of the skull base.

Abstract: We report a case of recurrent nasopharyngeal carcinoma postnasopharyngectomy, presenting with headaches. MRI revealed abnormal signals of the clivus with enhancement, and FDG PET/CT indicated intense uptake in the nasopharynx, clivus, and left neck lymph nodes. Bone SPECT/CT showed bony erosion and uptake in bilateral skull base areas. Biopsy confirmed aspergillosis. Despite the challenges in distinguishing tumor invasion from Aspergillus infection on MRI, bone SPECT/CT, and FDG PET/CT, the short postsurgery period and extensive uptake suggested skull base osteomyelitis., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: For a minimally invasive treatment approach to the anteromedial part of the anterior cranial fossa (ACF), a small incision and craniotomy of the posterolateral part of the ACF are preferable., Method: We described the concept and technique of suprapterional keyhole approach (SPKA), which uses an exoscope and endoscope to treat ACF lesions., Conclusion: The SPKA enables ACF observation from the lateral direction; the endoscope's extended viewing angles enable the observation of the anteromedial part of the ACF, including the bilateral olfactory groove. Facial skin and large scalp incisions are avoided, making this approach efficient for ACF lesions., (© 2024. The Author(s).)