Search Results (93)

A fossil bird (MLP-PV 15-I-7-52) from Marambio (Seymour) Island, Antarctica, is described, representing the best-preserved skull reported for a Cretaceous neornithine and associated postcranial elements. Morphological analysis of the articular portion of the mandible, the pterygoid, and the femur supports the assignment of this specimen to the genus Vegavis. The palatine morphology exhibits a combination of plesiomorphic and autapomorphic characters within Neognathae. Substantial differences in the size relationship between the ala preacetabularis and the femur, as well as differences between the femora of V. iaai and MLP-PV 15-I-7-52, indicate that the latter represents a new species of Vegavis. In addition, a third species of Vegavis is proposed based on the AMNH FARB 30899 specimen, previously assigned to V. iaai, which exhibits substantial differences with the above-mentioned specimens, particularly in the mandibular morphology. Full article

Dogs show exceptional olfactory sensitivity and are widely used in medical, rescue, military, and forensic applications, yet the determinants of individual and breed-level scent-work performance remain incompletely characterized. This review integrates evidence from the anatomy and physiology of the canine olfactory organ, neurobiological mechanisms of odor transduction and coding, and links between olfaction, memory, and emotion, alongside molecular genetics, evolution, domestication, and selective breeding. We synthesize findings indicating that complex nasal turbinates and specialized airflow patterns enhance odorant capture, while olfactory bulb circuitry and downstream connections to limbic and frontal networks support discrimination, learning, and affective modulation. Comparative and breed-focused studies suggest that skull morphology and breeding priorities can alter olfactory capacity, with shortened nasal anatomy associated with reduced functional potential in some lines. In applied contexts, detection success is strongly shaped by behavioral traits such as motivation, persistence, independence, and reward value, as well as by physical condition and environmental stressors that can impair search efficiency. Emerging literature further suggests that the gastrointestinal and upper airway microbiome, together with diet, housing, temperature, and workload, may influence sensory and cognitive readiness, although direct causal links to detection outcomes remain limited. Overall, canine olfactory performance reflects interactions among genetic–anatomical capacity, neurobehavioral factors, and environment, underscoring the value of standardized selection, training, welfare management, and future integrative research. Full article

Background/Objectives: Craniopharyngiomas (CPs) are rare, generally benign tumors predominantly located in the sellar and suprasellar regions, associated with significant morbidity and complex surgical management. Despite high overall survival rates, patients frequently experience complications including visual impairment, pituitary dysfunction, diabetes insipidus (DI), and hypothalamic syndrome. Among these, hypothalamic obesity (HO) represents one of the most clinically challenging sequelae, often occurring early, lacking standardized medical treatment, and leading to substantial comorbidity and reduced quality of life. This study reports a single-center experience focusing on the relationship between skull base anatomy, surgical approach selection, and endocrinological outcomes. Methods: A retrospective analysis was conducted on patients diagnosed with CPs who underwent surgery by a dedicated team at our Department from January 2014 to January 2024. The approaches used were endoscopic (ER) and transcranial (TR). Preoperative imaging (volumetric MRI and CT scans) was analyzed using 3DSlicer (open-source software) for anatomical modeling of the tumor and skull base. Clinical outcomes were evaluated through follow-up assessments by a team of neuroendocrinologists. Data on BMI changes, DI onset, and hypopituitarism were collected. Statistical analyses consisted of descriptive comparisons and exploratory regression models. Results: Of 18 patients reviewed, 14 met the inclusion criteria. Larger sphenoid sinus volumes were associated with selection of an endoscopic endonasal approach (p = 0.0351; AUC = 0.875). In ER cases, the osteotomy area was directly related to tumor volume, independent of other anatomical parameters. Postoperatively, a significant increase in BMI (22.39 vs. 26.65 kg/m²; p = 0.0049) and in the incidence of DI (three vs. nine cases; p-value 0.0272) was observed. No clear differential association between surgical approach and endocrinological outcomes emerged in this cohort. Conclusions: Quantitative assessment of skull base anatomy using 3D modeling may support surgical approach selection in patients with craniopharyngiomas, particularly in identifying anatomical settings favorable to endoscopic endonasal surgery. Endocrinological outcomes appeared more closely related to tumor characteristics and hypothalamic involvement than to the surgical route itself. These findings support the role of individualized, anatomy-informed surgical planning within a multidisciplinary framework. Full article

Background/Objectives: Managing large midline olfactory groove meningiomas is especially difficult in elderly patients who have limited physiological reserves. Here we describe a unique and dangerous geriatric case where we used new quantifiable anatomical measurements and developed a structured multidisciplinary preoperative and postoperative protocol to assist in all aspects of surgery. Case Presentation: A 68-year-old male with fronto-lobe syndrome and disability (astasia-abasia; Tinetti Balance Score of 4/16 and Gait Score of 0/12) as well as cognitive dysfunction (MoCA score of 12/30) and blindness bilaterally. Imaging prior to surgery demonstrated a very large olfactory groove meningioma which severely compressed both optic pathways at the level of the optic canals (up to 71% reduction in cross-sectional area of the optic nerves) and had complex vascular relationships with the anterior cerebral artery complex (210° contact surface). Due to significant cardiovascular disease and liver disease, his care followed a coordinated optimization protocol for the perioperative period. He underwent bifrontal craniotomy, initial early devascularization and then staged ultrasonic internal decompression (approximately 70% reduction in tumor volume) and finally microsurgical dissection of the tumor under multi-modal monitoring of neurophysiology. Discussion: We analyzed his imaging data prior to surgery using a standardized measurement protocol to provide quantitative measures of the degree of compression of the optic pathways (traction-stretch index = 1.93; optic angulation = 47.3°). These quantitative measures allowed us to make a risk-based evaluation of the anatomy and to guide our choices of corridors through which to dissect and remove the tumor. Following surgery, imaging studies demonstrated complete removal of the tumor with significant relief of the frontal lobe and optic apparatus from compression. His pathology showed that he had a WHO Grade I meningioma with an AKT1(E17K) mutation identified on molecular profiling. Conclusions: This case is intended to demonstrate the feasibility of integrating quantitative anatomical measurements into a multidisciplinary, protocol-based perioperative pathway to maximize the safety and effectiveness of the surgical removal of a complex and high-risk skull-base tumor. While the proposed quantitative indices are experimental and require additional validation, the use of a systematic approach such as this may serve as a useful paradigm for other complex skull-base cases. Full article

Background/Objectives: Anatomical variation in the ethmoid roof and lateral lamella play an important role in anatomical vulnerability during endoscopic sinus and skull base surgery. However, widely used classifications, including the Keros system, primarily focus on vertical depth and may not fully reflect the complex geometric relationship between the ethmoid roof, lateral lamella, and the anterior ethmoidal artery (AEA). This study aimed to characterize ethmoid roof and lateral lamella anatomy using high-resolution CT and to propose a descriptive radiological framework—the Akcan Classification—that integrates AEA exit patterns with multiple morphometric parameters. Given the complexity of thin skull base structures, interobserver reproducibility of all morphometric parameters was additionally assessed to ensure measurement robustness. Methods: High-resolution paranasal sinus CT scans from 175 adults (350 sides) were retrospectively evaluated. Measurements included ethmoid roof width, lateral lamella depth, anterior–posterior length, lamellar angle, AEA–lamella distance, and sinonasal anatomical variations. Interobserver reliability was quantified using ICCs. AEA morphology was categorized as in-canal (Type 1), partially suspended (Type 2), or fully suspended (Type 3) based on radiological appearance of bony canalization. Appropriate statistical tests were used to compare morphometric features across groups. Results: Suspended AEA configurations demonstrated progressively wider ethmoid roofs, deeper lateral lamellae, steeper lamellar inclination, and shorter AEA–lamella distances (all p < 0.001). Supraorbital ethmoid cells were more frequently observed in Type 3 cases (p < 0.001). Other anatomical variations showed no significant association with ethmoid roof morphology. Interobserver reliability was excellent for all measurements (ICC range 0.87–0.94). Conclusions: The findings suggest that AEA configuration is associated with broader patterns of ethmoid roof and lateral lamella morphology. Rather than serving as a validated predictor of surgical outcomes, the Akcan Classification provides a structured anatomical and radiological descriptor that complements depth-based systems such as the Keros classification. The high reproducibility of measurements supports its potential utility for standardized anatomical assessment and preoperative radiological interpretation, while further studies incorporating surgical correlation are required. Full article

Background: The sphenoid sinus is essential for transsphenoidal surgical accesses to the sellar and parasellar regions because of its anatomic proximity to vital vascular and neurologic structures such as the internal carotid artery, optic nerve, and cavernous sinus. The high degree of morphological variability of the sphenoid sinus has a significant impact on surgical technique and the risk of intraoperative complications. Detailed knowledge of individual anatomy is therefore crucial for the safety and efficacy of transsphenoidal approaches. Objectives: This review aims to conduct a systematic analysis of the current scientific literature on anatomical variations in the sphenoid sinus and their clinical relevance in surgical interventions to the skull base. Special attention is paid to the influence of morphological features on surgical strategies to pathological processes in this area and postoperative outcomes. Materials and Methods: A systematic review of the literature was conducted according to PRISMA 2020 guidelines. The PubMed, Scopus, Web of Science, and Google Scholar databases were searched for the period March 2010 to March 2025. Keywords such as “sphenoid sinus”, “anatomical variations”, “transsphenoidal surgery” and “skull base” were used. Original studies, systematic reviews, and meta-analyses focused on the anatomy, pneumatization, and surgical significance of sphenoid sinus variations are included. Quality and relevance criteria for published material were considered in the selection of articles. Results: The most commonly identified anatomic variations included sellar and lateral pneumaticity, the presence of Onodi cells, multiple and deviated septa, and dehiscence of the posterior wall of the sphenoid sinus and prolapse into its cavity of the internal carotid artery. These variations are associated with an increased risk of intraoperative vascular injury, visual deficit, and postoperative liquorrhea. Accurate preoperative assessment by high-resolution computed axial tomography and magnetic resonance imaging, as well as the use of intraoperative neuronavigation, are critical to reduce surgical risk. Conclusions: Anatomic variations in the sphenoid sinus are an essential factor to consider when planning and performing transsphenoidal surgical accesses. An individualized approach based on detailed diagnostic imaging analysis and neuronavigation technologies contributes to a higher safety of the performed surgical interventions, a better radicality of tumor resection and more favorable postoperative outcomes. Full article

Background/Objectives: The ascending pharyngeal artery (APA) exhibits considerable variability in origin. Understanding its anatomy is essential for head and neck surgery, endovascular procedures, and skull base approaches. This study aimed to (1) systematically characterize APA origin sites, (2) evaluate bilateral patterns, and (3) establish a comprehensive sequential classification system for external carotid artery (ECA) branching. Methods: Bilateral computed tomography angiography assessment was performed in 85 patients (170 carotid axes; 54 men, 31 women; mean age 69 ± 10 years). APA origins were classified into six types: Type 0 (absent), Type I (ECA medial wall), Type II (ECA posterior wall), Type III (occipitopharyngeal trunk), Type IV (internal carotid artery), and Type V (other origins). A novel sequential classification system (S-types) documented the complete ECA branching order. Results: APA was absent in 14.71% of cases; APA’s absence or internal carotid origin was noted in 19.41% of cases. Type I occurred in 26.47%, Type II in 35.88%, Type III in 17.06%, Type IV in 4.71%, and Type V in 1.18%. Forty distinct S-types were identified, representing the most comprehensive documentation of ECA branching diversity. No statistically significant side-related (χ² = 42.12, p = 0.379) or gender-related (χ² = 49.81, p = 0.138) differences were found. Twenty-three types occurred in fewer than five cases each. Conclusions: This first comprehensive sequential classification system reveals extraordinary anatomical diversity in ECA branching patterns. The absence of predictable side or gender patterns necessitates bilateral preoperative imaging for surgical planning. Full article

The Cape Genet (Genetta tigrina) is one of the exotic mammal species that are becoming popular as pets. Although it is possible to find some references in the literature regarding Genetta spp. and viverrids, the information about this animal remains scarce and incomplete, starting from the anatomy, a discipline that lays the foundations for deeper knowledge of a species. The aim of the present study is to identify head structures of the Cape Genet, including the skull, brain components, and the dental formula, providing for the first time a three-dimensional anatomical model of the skull, thanks to the help of advanced diagnostic imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI), defining the ideal parameters and protocols of CT, MRI, and anesthesia for this procedure in this species. Results highlight the value of CT and MRI as study tools, enabling clear visualization of cranial structures and offering a potential reference atlas for clinicians and researchers. Full article

Background/Objectives: The cavernous segment of the internal carotid artery (ICA) is a critical neurovascular structure with complex cranial nerve relationships. Understanding its morphometric variability is essential for safe microsurgical and endovascular procedures. This study aimed to characterize the morphometry of the cavernous ICA using Magnetic resonance imaging (MRI) and assess associations with demographic variables. Methods: A retrospective observational study was conducted on 135 MRI scans of adult patients, distributed among 79 women and 56 men with an average age of 50.8 years, without cerebrovascular pathology, performed between March 2023 and January 2025. The diameters of the left and right cavernous ICA and the intercarotid distance were measured using RadiAnt DICOM Viewer. Statistical analyses included descriptive statistics, t-tests, correlations, and multivariate regression models adjusted for age and sex. Principal component and cluster analyses were applied to identify morphometric patterns. Results: The mean left and right ICA diameters were both 5.09 ± 0.65 mm, with a mean intercarotid distance of 17.4 ± 4.22 mm. No age-related associations were found (p > 0.05). Male patients showed significantly larger right ICA diameters (p = 0.008). Bilateral symmetry was confirmed (p > 0.05). Two morphometric clusters were identified: Morphotype 1 (larger ICA caliber and narrower spacing) and Morphotype 2 (smaller caliber and wider spacing), showing a significant sex distribution difference (p = 0.012). Conclusions: The cavernous ICA demonstrates stable bilateral symmetry with minor sex-dependent differences. Morphometric characterization supports safer planning of transsphenoidal, endovascular, and skull-base surgeries by reducing the risk of iatrogenic neurovascular injury. Full article

Background/Objectives: The lamina terminalis is an important anatomical structure located at the anterior wall of the third ventricle and surrounded by critical neurovascular elements. Precise and safe surgical access to this region requires detailed anatomical knowledge and mastery of skull base approaches. This study aims to anatomically illustrate and compare the pterional, one-piece orbitozygomatic, and two-piece orbitozygomatic craniotomies as approaches to the lamina terminalis cistern. The objective is to provide a comprehensive photographic guide to support neurosurgeons and residents in learning these techniques. Methods: Two formalin-fixed, silicone-injected adult cadaveric heads were dissected under an operating microscope. Standard pterional, one-piece orbitozygomatic, and two-piece orbitozygomatic approaches were performed. Key anatomical landmarks and surgical steps were documented photographically. Osteotomies, dural openings, and basal drilling techniques were systematically applied to maximize exposure of the lamina terminalis region while preserving critical neurovascular structures. Results: The results demonstrate that all three approaches effectively expose the lamina terminalis cistern and related vascular structures. By highlighting the trajectory, osteotomies, and neurovascular anatomy, the anatomical dissections provide valuable visual guidance. These findings are intended to support neurosurgical education by illustrating the strengths of each approach in a comparative context. Conclusions: This study offers detailed anatomical visualization of three key approaches to the lamina terminalis. The stepwise dissections and high-resolution images are intended as an educational guide to assist neurosurgeons and residents in mastering these techniques. Such anatomical understanding is vital for safe, effective surgical interventions involving the anterior skull base and vascular pathologies. Full article

The accurate reconstruction of craniofacial defects requires the precise segmentation and mirroring of healthy anatomy. Conventional workflows rely on manual interaction, making them time-consuming and subject to operator variability. This study developed and validated a fully automated digital pipeline that integrates deep learning–based segmentation with algorithmic mirroring for craniofacial reconstruction. A total of 388 cranial CT scans were used to train a three-dimensional nnU-Net model for skull and mandible segmentation. A Principal Component Analysis–Iterative Closest Point (PCA–ICP) algorithm was then applied to compute the sagittal symmetry plane and perform mirroring. Automated results were compared with expert-generated segmentations and manually defined symmetry planes using Dice Similarity Coefficient (DSC), Mean Surface Distance (MSD), Hausdorff Distance (HD), and angular deviation. The nnU-Net achieved high segmentation accuracy for both the mandible (mean DSC 0.956) and the skull (mean DSC 0.965). Mirroring results showed minimal angular deviation from expert reference planes (mandible: 1.32° ± 0.71° in defect cases, 1.58° ± 1.12° in intact cases; skull: 1.75° ± 0.84° in defect cases, 1.15° ± 0.81° in intact cases). The presence of defects did not significantly affect accuracy. This automated workflow demonstrated robust performance and clinical applicability, offering standardized, reproducible, and time-efficient planning for craniofacial reconstruction. Full article

Background: The sphenoidal emissary foramen (SEF) is an inconstant foramen of the sphenoid bone that facilitates venous communication between the pterygoid venous plexus and the cavernous sinus. Understanding its prevalence and laterality is crucial to preventing vascular injury during skull base procedures. Methods: A cross-sectional observational study was conducted on 133 adult Chilean dried skulls. Each specimen was examined both internally and externally to record SEF presence and laterality. Three independent observers performed the assessments under direct lighting, achieving excellent interobserver agreement (κ = 0.87, 95% CI = 0.81–0.92). Descriptive statistics, Chi-square tests, and Cramer’s V coefficients were calculated to evaluate side dominance and effect size at a significance level of p < 0.05. Results: The SEF was present in 40.17%. Bilateral foramina were observed in 26.79%, and unilateral SEF in 13.38%. Left-sided SEF (9.12%) was more common than right-sided SEF (4.26%), showing a significant difference (p = 0.03; Cramer’s V = 0.19, 95% CI = 0.02–0.33). This mild but significant left-sided prevalence indicates slight directional asymmetry rather than functional lateralization. Conclusions: The Chilean prevalence of the SEF lies within the mid-range of international data and closely aligns with Brazilian osteological reports. Although a minor left-sided predominance was observed, the effect size was weak (Cramer’s V = 0.19), reinforcing the interpretation of the SEF as a normal morphological variability rather than a true anatomical variant. Precise preoperative identification of the SEF is crucial to reduce the risk of venous injury and avoid unintentional penetration. Full article

This study aimed to characterize the computed tomographic (CT) dimensions and contrast attenuation properties of the equine eye. CT scans from 21 horses without ocular abnormalities were analyzed to obtain detailed ocular measurements and attenuation values. In addition, cranial measurements, such as nasal–occipital length and zygomatic width, were incorporated to explore potential anatomical relationships between the skull and intraocular structures. Although most correlations between cranial and ocular parameters were weak, statistically significant associations—particularly those involving lens dimensions and anterior chamber measurements—suggest that skull morphology may exert a subtle influence on ocular anatomy. Full article

Background/Objectives: The Eustachian tube (ET) is a physiological channel connecting the middle ear with the external atmosphere. The ET plays a role in maintaining the pressure balance of the middle ear, protecting it from pathogen invasion, and cleaning secretions. Eustachian tube dysfunction (ETD) can lead to middle ear diseases in animals. The ET morphological structure are different across species. Therefore, we aim to compare the anatomical and morphological of ET across species. Methods: The combined skull base–nasal approach was used to anatomy ET. Hematoxylin-eosin, luxol fast blue myelin and immunohistochemical Staining were used to observe the morphology of ET. Results: There were significant differences in the size and structure of ET among species: the rodents ET (mouse: 1.152 ± 0.084 mm; rat: 3.738 ± 0.04355 mm) is characterized by cartilage and obvious bubbles; while the miniature pigs ET (32.34 ± 2.157 mm) has a chondroid conical structure similar to that of humans. ET inflammation model was built by intro-tympanic injection of lipopolysaccharide (LPS). NADPH oxidase 2 (NOX2) significantly increased by 38.6% in inflamed mice, causing ET oxidative stress. The expressions of inflammatory factors interleukin-1β (IL-1β) and cyclooxygenase-2 (COX2) increased by 28.4% and 30.8%, resulting in thickening of the ET mucosa and infiltration of inflammatory cells. Conclusions: The combined skull base–nasal approach was an effective method to anatomy ET across species. The morphology of ET varied across species and NOX2 might play an important role in ET inflammation. Full article

Objectives: Anterior petrosectomy is a challenging neurosurgical procedure requiring precise identification and preservation of multiple critical structures. This technical note explores the feasibility of using real-time near-infrared indocyanine green (NIR-ICG) fluorescence with white light overlay to enhance visualization of the petrous internal carotid artery (ICA) during transpetrosal drilling. We aimed to assess its utility for planning and performing modified Dolenc–Kawase drilling. Methods: We integrated NIR-ICG and white light overlay using a robotic microscope with simultaneous visualization capabilities. This technique was applied to improve neurovascular preservation and skull base landmark identification. Intraoperative video frames and images were captured during an anterior transpetrosal approach for a petroclival meningioma, with technical details, surgical time, and feedback documented. Results: Real-time NIR-ICG with white light overlay successfully identified the posterior genu, horizontal petrosal segment, anterior genu, and superior petrosal sinus. It facilitated precise localization of cochlear landmarks, enabling tailored drilling of the Dolenc–Kawase rhomboid according to patient anatomy and accommodating potential anatomical variants. Conclusions: This approach could enhance intraoperative safety and improve exposure, possibly reducing neurovascular risks without extending operative time. It may serve as a valuable adjunct for complex skull base surgeries. Full article