Background: The caroticoclinoid bar (CCB) or caroticoclinoid foramen (CCF) represents a well-described ossified variant of the skull base. It corresponds to an osseous bridge (resulting after homonymous ligament ossification) between the anterior and middle clinoid processes (ACPs and MCPs) surrounding the internal carotid artery (ICA)’s cavernous segment. Although extensive research has been performed on this clinically significant entity, only a few studies have been conducted on its effect on the ICA. The current study on dried skulls, using computed tomography (CT) and computed tomography angiography (CTA) scans, aimed to investigate the CCB’s presence and potential morphological stenosis patterns. Methods: One hundred (100) dried adult skulls and one hundred sixty (160) skulls from CT scans of patients were obtained (a total of 520 observations). To further calculate the ICA diameter (at the ACP-MCP region) and correlate the resulting dimeters with all potential morphological stenosis patterns of the CCB, thirty (30) CTAs of patients free of the variant were selected. Results: Concerning the osseous pattern morphology, of the total of 520 sides, the CCB was identified in 17.1%, the complete variant (creating a caroticoclinoid foramen-CCF) was calculated in 11.5%, and the incomplete one was calculated in 5.6%. No side, sex, or age impact was identified for the CCB presence. Concerning the ICA dimensions, its diameter was calculated to be between 4 and 5 mm. Thus, we observed three morphological stenosis patterns of the CCF. A low-risk pattern of stenosis (>5 mm diameter) was observed in 40 CCFs (44.9%), an intermediate risk of stenosis (4–5 mm diameter) in 38 CCFs (38.2%), and a high risk of stenosis (<4 mm diameter) was depicted in 15 CCFs (16.8%). Conclusions: In the present study, we investigated the CCF presence and potential morphological stenosis patterns by calculating and correlating the ICA diameter. In 16.8% of the current sample with CCFs (irrespective of their morphology), we observed that the ICA is probably at a high risk of compression. Radiologists and neurosurgeons intervening in the area should preoperatively diagnose the possibility of ICA compression in this area.

Purpose: This meta-analytical systematic review aims at investigating the variability of the pterion, focusing on its morphological types and precise distances from various bony landmarks. Additionally, the neurosurgical significance of this critical cranial landmark is examined in depth. Methods: The systematic review was conducted following PRISMA 2020 and Evidence-based Anatomy Workgroup guidelines for anatomical studies. The risk of bias was assessed using the Anatomical Quality Assurance Tool (AQUA). The meta-analysis was performed using R programming software and RStudio, employing the “meta” and “metafor” packages. Results: A total of 79 studies were included, encompassing 18,694 skull sides. The sphenoparietal type was identified as the most prevalent pterion variant, with a pooled prevalence of 78.54%. The epipteric type followed at 8.41%, while the frontotemporal (5.74%) and stellate (4.26%) types were the rarest. Significant differences in the prevalence of the epipteric, frontotemporal, and stellate types were observed across different nationalities. However, sex, side, and study type did not significantly influence pterion morphological variation. The study also extracted and calculated the distances between the pterion and key anatomical landmarks, including the midpoint of the zygomatic arch, the frontozygomatic suture, the mastoid process, and the external acoustic meatus. Conclusion: This study offers critical anatomical insights by accurately mapping the pterion’s location relative to essential cranial landmarks. These findings are vital for neurosurgical planning, particularly for procedures involving the anterior and middle cranial fossae. The detailed anatomical data provided can enhance the precision and safety of neurosurgical interventions, ultimately improving patient outcomes.

Background: The morphology of the occipital condyles (OCs) and foramen magnum (FM) is critical for neurosurgical planning and forensic identification. However, pooled reference values and the impact of study-level moderators on morphometric estimates remain underexplored. Methods: A systematic review and meta-analysis were conducted to estimate pooled morphometric values of the OCs and FM. Databases were searched for studies reporting relevant data in adult human subjects. A random-effects model was used to calculate pooled means and mean differences (MDs) by sex and side (left vs. right). Risk of bias and study quality were assessed. Subgroup analyses were conducted based on study design (osteological vs. imaging) and geographical region. Meta-CART (classification and regression trees) was used to explore moderator interactions and identify data-driven subgroups contributing to heterogeneity. Results: A total of 61 studies comprising 8010 adult skulls met the inclusion criteria. Substantial heterogeneity was observed across studies; most were assessed as having low-to-moderate methodological quality and a high risk of bias. The pooled mean values were as follows: OC length (OCL): 21.51 mm, OC width (OCW): 11.23 mm, OC thickness (OCT): 9.11 mm, FM length (FML): 35.02 mm, and FM width (FMW): 28.94 mm. Morphometric values reported in imaging-based studies were consistently lower than those from osteological studies. Evident sexual dimorphism was identified, with males exhibiting larger dimensions than females. The most pronounced sex-based mean differences (MDs)—approximately 2 mm—were found in OCL, FML, and FMW. In contrast, differences in OCT and OCW were under 1 mm. No significant side-related asymmetries were observed overall. Subgroup analysis revealed that sex-related MDs were more prominent in imaging studies, particularly for the right OCL and OCW. Meta-CART analysis identified study design as the strongest moderator for OCL, OCW, and FML. Sexual dimorphism was more pronounced in imaging studies but statistically insignificant in osteological samples. Furthermore, sex emerged as a stronger predictor for OCL than OCW, while geographical region had a greater impact on OCW. For OCT, geographical region was the main influencing factor, whereas sex was the primary moderator for FMW. Conclusions: OC and FM morphometry exhibit substantial heterogeneity across studies. Imaging-based methods more effectively detect sex-related differences, underscoring their utility in forensic identification and neurosurgical planning. These findings emphasize the need for more standardized, high-quality morphometric research to support population-specific anatomical reference data.

Background: The anatomical relationship between the carotid arteries (CAs) and the hyoid bone (HB) has significant clinical implications. The present study investigates the spatial relationship between the HB and common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), and carotid bifurcation (CB), analyzing their morphological variants and topographical associations. Materials and Methods: Computed tomography angiographies (CTAs) from 100 patients (50 males, 50 females; mean age 62.2 ± 14.5 years) were analyzed. Measurements included the HB greater horn length (GHL) and greater horn angle (GHA), CA distances, and classification of relationships of the CAs with the HB. Results: The mean GHL was 27.72 ± 3.91 mm, and the mean GHA was 110.36 ± 6.06 degrees. Males exhibited significantly longer GHs than females (p < 0.001). Suprahyoid bifurcations occurred in 35.5% of cases, with a mean CCA-GH distance of 4.54 ± 2.67 mm. Infrahyoid bifurcations were identified in 64.5% of cases, with mean ECA-GH and ICA-GH distances of 4.10 ± 3.11 mm and 6.72 ± 3.85 mm, respectively. GHL significantly influenced these distances. Type 6 (ECA positioned laterally to the GH) was the most prevalent carotid–hyoid configuration (18.5%). Conclusions: The present study provides essential insights into the topographical variability of the CAs relative to the HB, offering valuable guidance for surgical planning and vascular risk assessment. These findings are crucial for procedures such as carotid endarterectomy, where the proximity of the carotid arteries to the hyoid bone impacts the risk of vascular injury. Further research is warranted to explore the clinical implications of these anatomical relationships.

The jugular foramen (JF) is a structurally complex region of the skull base with critical neurosurgical relevance. This anatomical imaging study aimed to investigate the morphological variability of the JF by analyzing both its intracranial and extracranial orifices using a combination of osteological assessment and computed tomography (CT) scans.A total of 200 adult skulls (100 dried specimens and 100 CT scans) were examined bilaterally. The JF was classified based on the presence, number, and completeness of intrajugular processes (IJPs). Morphometric measurements of horizontal and transverse diameters were performed, and statistical analyses were used to evaluate differences by sex, laterality, and between the intracranial and extracranial aspects.IJPs were significantly more common in the intracranial orifice (41%) compared to the extracranial (19.5%), with type 1a (incomplete septation) being the most frequent. A right-sided predominance was observed for intracranial JF dimensions ( p = 0.036), while no significant sex-related differences were found. The morphometric analysis revealed that JF compartments became progressively narrower with an increasing number of IJPs. A moderate positive correlation was found between intracranial and extracranial measurements ( B = + 0.357, p < 0.001).This study provides a detailed anatomical and radiological analysis of JF variability, emphasizing its clinical implications for skull base surgery. The findings highlight the importance of preoperative imaging in identifying IJP-related compartmentalization, which may impact surgical planning and risk assessment. Future research should aim to better correlate bony septations with neurovascular content to define their relevance in both surgical and pathological contexts. Clinical trial number Not applicable.