Search Results (84)

Background: Identifying the etiological factors of syringomyelia, which can cause progressive neurological deficits in the spinal cord, is critically important for both diagnosis and treatment. This study aimed to assess the cranial morphometric features of patients with idiopathic syringomyelia by conducting comparative analyses with individuals diagnosed with Chiari Type I, Chiari Type I accompanied by syringomyelia, and healthy controls, in order to elucidate the potential structural contributors to the pathogenesis of idiopathic syringomyelia. Methods: In this retrospective and comparative study, a total of 172 patients diagnosed with Chiari Type I and/or syringomyelia between 2016 and 2024, along with 156 radiologically normal individuals, were included. The participants were categorized into four groups: healthy controls, Chiari Type I, Chiari Type I with syringomyelia, and idiopathic syringomyelia (defined as syringomyelia without an identifiable cause). Midline sagittal T1-weighted MR images were used to obtain quantitative measurements of the posterior fossa, cerebellum, intracranial area, and foramen magnum. All measurements were stratified and statistically analyzed by sex. Results: In cases with idiopathic syringomyelia, both the posterior fossa area and the cerebellum/posterior fossa ratio differed significantly from those of healthy controls. In male patients, the foramen magnum diameter was significantly larger in the Chiari + syringomyelia group compared with the idiopathic group. A significant correlation was found between the degree of tonsillar descent and selected morphometric parameters in female subjects, whereas no such correlation was observed in males. Both Chiari groups exhibited significantly smaller posterior fossa dimensions compared with the healthy and idiopathic groups, indicating greater neural crowding. Additionally, in Chiari Type I patients, increasing degrees of tonsillar descent were associated with a decreased incidence of syringomyelia. Conclusions: Anatomical variations such as a reduced posterior fossa area or altered foramen magnum diameter may contribute to the pathogenesis of idiopathic syringomyelia. Cranial morphometric analysis appears to offer diagnostic value in these cases. Further prospective, multicenter studies incorporating advanced neuroimaging modalities, particularly those assessing cerebrospinal fluid dynamics, are warranted to better understand the mechanisms underlying syringomyelia of unknown etiology. Full article

Although cranial growth has been extensively explored, forensic and biological anthropology lack a formal incorporation of how cranial growth processes impact the adult phenotype and downstream biological profile estimations. Objectives: This research uses an ontogenetic framework to identify when interlandmark distances (ILDs) stabilize during growth to reach adult levels of variation and to evaluate patterns of cranial sexual size dimorphism. Methods: Multivariate adaptive regression splines (MARS) were conducted on standardized cranial ILDs for 595 individuals from the Subadult Virtual Anthropology Database (SVAD) and the Forensic Data Bank (FDB) aged between birth and 25 years. Cross-Validated R-squared (CVRSq) values evaluated ILD variation explained by age while knot placements identified meaningful changes in ILD growth trajectories. Results: Results reveal the ages at which males and females reach craniometric maturity across splanchnocranium, neurocranium, basicranium and cross-regional ILDs. Changes in growth patterns observed here largely align with growth milestones of integrated soft tissue and skeletal structures as well as developmental milestones like puberty. Conclusions: Our findings highlight the variability in growth by sex and cranial region and move forensic anthropologists towards recognizing cranial growth as a mosaic, continuous process with overlap between subadults and adults rather than consistently approaching subadult and adult research separately. Full article

The arboreal rodent Oecomys catherinae, which has a wide geographic distribution across Brazilian biomes, provides a model for investigating environmental influences on morphological variation. We assessed craniodental differences between the Atlantic Forest and Cerrado biomes, as well as along latitudinal gradients, using 45 specimens from 18 localities. Linear morphometric analyses (21 measurements) revealed no significant sexual dimorphism, allowing for pooled analyses. Principal Component Discriminant Analysis (DAPC) confirmed significant morphological divergence between biomes (72% accuracy, p < 0.01). We identified bony palate length (BPL) as the most discriminating variable, with higher values in the Atlantic Forest, suggesting a possible dietary adaptation in response to ecological pressures. Latitudinal effects were modest (adjusted R² = 0.05) although significant (F_1,43 = 3.63; p = 0.03), with southern populations exhibiting larger cranial dimensions than northern ones. We conclude that biome type and latitude played important roles in shaping cranial morphology in O. catherinae populations. Full article

Geometric morphometrics is performed on different species in different contexts. Here, the aim was to investigate morphological differences in the head of the Sanmartinero Creole bovine to examine head shape variations between sexes using geometric morphometric methods. A sample of cranial pictures of 43 animals (13 males and 30 females) was obtained, and form (size + shape) was studied by means of geometric morphometric techniques using a set of 14 landmarks. This approach eliminated potential dietary effects, ensuring that the observed shape variations were primarily due to intrinsic morphological differences. Sexual dimorphism was found in form (for both size and shape) of the head of the Sanmartinero Creole bovine breed. Males had significantly larger heads based on centroid size (U = 714, p = 0.0004), confirming true sexual size differences, and Principal Component Analysis revealed overlapping head shapes with sexual dimorphism concentrated at midline sagittal landmarks (between the most rostral and caudal orbit points) and paired lateral points, indicating that males have broader and longer heads. The two evaluated characters (head size and shape) are of special interest for the conservation of the breed, especially in those cases whose objectives are to maintain the uniqueness, distinctiveness, and uniformity of the populations. This study analyzed animals subjected to the same feeding program, ensuring the elimination of additional variables. Full article

Odontogenesis, the development of teeth, is a complex, multistage process that unfolds from early embryogenesis through tooth eruption and maturation. It serves as a classical model of organogenesis due to the intricate reciprocal interactions between cranial neural crest-derived mesenchyme and oral epithelium. This narrative review synthesizes current scientific knowledge on human tooth development, tracing the journey from the embryological origins in the first branchial arch to the formation of a fully functional tooth and its supporting structures. Key morphogenetic stages—bud, cap, bell, apposition, and root formation—are described in detail, highlighting the cellular events and histological features characterizing each stage. We discuss the molecular and cellular regulatory networks that orchestrate odontogenesis, including the conserved signaling pathways (Wnt, BMP, FGF, SHH, EDA) and transcription factors (e.g., PAX9, MSX1/2, PITX2) that drive tissue patterning and cell differentiation. The coordinated development of supporting periodontal tissues (cementum, periodontal ligament, alveolar bone, gingiva) is also examined as an integral part of tooth organogenesis. Finally, developmental anomalies (such as variations in tooth number, size, and form) and the fate of residual embryonic epithelial cells are reviewed to underscore the clinical significance of developmental processes. Understanding the normal course of odontogenesis provides crucial insight into congenital dental disorders and lays a foundation for advances in regenerative dental medicine. Full article

Background and Objectives: The foramen lacerum (FL), located at the base of the skull, is generally considered the safest anatomical pathway for accessing the internal carotid artery (ICA) and the vidian canal (VC) during surgical procedures. We aimed to evaluate the morphometric characteristics of FL, VC, and related structures. Materials and Methods: This study utilized cranial computed tomography (CT) images obtained between 2016 and 2018 at Balıkesir University Faculty of Medicine for various clinical indications. A retrospective analysis was performed on cranial CT images from 77 patients, comprising 42 females and 35 males. The length and width of the FL, the length of the VC, and the angles formed between the VC and the pterygosphenoidal fissure and between the VC and the palatovaginal canal were measured. All measurements were performed using the three-dimensional (3D) Slicer software to ensure precision and consistency. Results: Males had significantly longer right and left FL lengths and left FL width than females (p < 0.05). No significant gender-based differences were found in VC length on either side. The angle between the VC and the pterygosphenoidal fissure was significantly larger in males (p < 0.05). Additionally, increased FL length and width were significantly correlated with larger angles between the VC and the pterygosphenoidal fissure in all subjects (p < 0.05). The anatomical variations of the FL Type 1 (normal) were identified as the most prevalent configuration across the study population. Type 2 (canal-shaped) ranked as the second most frequent variant in females, whereas Type 3 (bridged) was the second most commonly observed form in males. Conclusions: Preoperative identification of FL anatomical variations, which differ between individuals and sexes, may enhance the safety of skull base surgeries and minimize postoperative complications. The morphometric data presented in this study provide valuable guidance for clinicians planning interventions involving the FL and surrounding structures, and contribute valuable insights to anatomists regarding regional morphology. Full article

Background and Clinical Significance: Cavum septum pellucidum (CSP) and cavum vergae (CV) are anatomical variations that may persist into childhood, adolescence, or adulthood. When these cavities become abnormally large, they are classified as cysts. The mechanism leading to expansion is poorly understood. Although rare, symptomatic CSP and CV cysts can present with a wide range of clinical manifestations. Case Presentation: A 20-year-old Caucasian male presented with progressively worsening symptoms over several months including persistent headaches and dizziness. Neurological evaluation showed no abnormalities, with intact cranial nerve function, normal muscle strength, and no signs of paresis. Imaging identified CSP and CV cysts causing obstructive hydrocephalus. MRI findings confirmed progressive cyst enlargement and obstruction of intraventricular foramen. The patient underwent neuroendoscopic fenestration of the cyst with resolution of both hydrocephalus and the symptoms. A CT and MRI scan of the brain performed 12 years before revealed a developmental variant, showing no evidence of cyst formation or ventricular enlargement and without hydrocephalus at that time. This case provides a rare opportunity to observe cyst growth dynamics over time. Conclusions: This case presents the importance of recognizing symptomatic CSP and CV cysts as rare but significant causes of obstructive hydrocephalus. The progression from a developmental variant to cyst formation over time illustrates the value of long-term imaging follow-up in such cases. Neuroendoscopic fenestration provided complete resolution of symptoms, demonstrating the effectiveness of surgical intervention in such cases. Full article

Cranial sutures play critical roles in load distribution and neuroprotection, with their biomechanical performance intimately linked to morphological complexity. The purpose of this study was to investigate the effect of different morphologies of cranial sutures on their biomechanical behavior. Based on the different morphologies of the cranial sutures, six groups of finite element models (closed, straight, sine wave, tight sinusoidal wave, layered sinusoidal wave, and layered sinusoidal wave + sutural bone) of the bone–suture–bone composite structures that ranged from simple to complex were constructed. Each model was subjected to 50 kPa impact and 98 N bilateral tensile loads to evaluate von Mises stress and total deformation variations across all groups under combined loading conditions. Key findings reveal that morphological complexity directly governs stress dynamics and mechanical adaptation; layered sinusoidal configurations delayed peak stress by 19–36% and generated elevated von Mises stresses compared to closed sutures, with stress concentrations correlating with interfacial roughness. Under impact, sutures exhibited localized energy dissipation (<0.2 μm deformation), while tensile loading induced uniform displacements (≤11 μm) across all morphologies (p > 0.05), underscoring their dual roles in localized energy absorption and global strain redistribution. Craniosacral therapy relevant forces produced sub-micron deformations far below pathological thresholds (≥1 mm), which implies the biomechanical safety of recommended therapeutic force. Staggered suture–bone in open sutures (31.93% closure rate) enhances shear resistance, whereas closed sutures prioritize rigidity. The findings provide mechanistic explanations for suture pathological vulnerability and clinical intervention limitations, offering a quantitative foundation for future research on cranial biomechanics and therapeutic innovation. Full article

Background: Childhood obesity and overweight conditions impact systemic health and craniofacial development. Objectives: This review assessed the influence of elevated body mass index (BMI) on craniofacial morphology, considering age, sex, and ethnicity. Methods: A comprehensive search of Scopus, Web of Science, Embase, Cochrane, PubMed, and OpenGrey was conducted following PRISMA guidelines. Ten cross-sectional studies involving 1383 individuals aged 6 to 18 years were included. The sample comprised 812 females and 571 males, with most studies focusing on adolescents aged 12–18 years of different ethnicities depending on the study. Craniofacial structures were compared between overweight/obese and normal weight groups through cephalometric analysis. Study quality was assessed using the Newcastle–Ottawa Scale (NOS). Results: Overweight and obese individuals showed significant craniofacial changes, including increased anterior cranial base length, maxillary and mandibular dimensions, bimaxillary prognathism, and greater soft tissue thickness. These alterations may be influenced by differences in tissue composition, hormonal fluctuations, fat-to-bone ratio, and metabolic disorders. Variations in skeletal divergence, dental alignment, and airway space were also observed. The methodological quality ranged from moderate to high. Conclusions: Excess weight during growth is linked to distinct craniofacial alterations. Orthodontic diagnostics should integrate metabolic and hormonal considerations to optimize treatment outcomes. These changes should be carefully considered by orthodontists and pediatric dentists. Longitudinal studies are needed to understand the long-term effects of obesity on craniofacial development. Full article

(1) Introduction: The main way of spreading the herpes simplex virus 1 (HSV-1) is through direct contact, as the virus enters the host via mucous membranes. Ocular infection can occur as a primary infection or as a recurrent one. The movement of HSV-1 along the ophthalmic branch of the fifth cranial nerve from its latency phase in the trigeminal ganglion and its activation represent a process influenced by various symbiotic factors, such as environmental conditions and the host’s genetic characteristics. The aim of this study was to assess the frequency of IL28 (rs12980275) and (rs8099917) in recurrent ocular HSV infections. (2) Materials and methods: The study included 60 patients aged over 18, of both sexes, all of whom had a history of herpes simplex labialis (HSL). Patients were tested for HSV-1-specific IgG antibodies, and seropositive individuals were genotyped for single nucleotide polymorphisms (SNPs) rs12980275 and rs8099917. A total of 57 seropositive patients were included in the study. (3) Results: A statistically significant association was found between recurrent HSV keratitis (HSK) and heterozygous GT rs8099917 and homozygous TT rs8099917, as well as heterozygous AG rs12980275 and homozygous AA rs12980275 (p < 0.01). Interestingly, patients with homozygous GG polymorphism for both genotypes GG rs8099917 and GG rs12980275 did not develop recurrent HSV keratitis. (4) Conclusion: The most frequent SNP variations in patients with recurrent HSV disease were heterozygous AG rs12980275 (61.40%) and heterozygous GT rs8099917 (52.63%). Patients with recurrent HSV keratitis lacked the homozygous GG polymorphism in both GG rs8099917 and GG rs12980275 genotypes, suggesting that HSV-seropositive individuals expressing these genotypes may have lower predisposition to develop recurrent stromal HSV keratitis. Full article

Continuous metrics of cerebral autoregulation (CA) assessment have been developed using various multimodal cerebral physiological monitoring devices. However, CA regional disparity remains unclear in states of health and disease. Leveraging existing archived data sources, we preliminarily evaluated regional hemispheric disparity in CA using the near infrared spectroscopy (NIRS)-derived cerebral oximetry index (COx/COx-a). Along with bilateral NIRS, regional cerebral oxygen saturation, arterial blood pressure, cerebral perfusion pressure, and bilateral COx/COx-a were derived using three different temporal resolutions—10 s, 1 min, and 5 min—based on non-overlapping mean values. The regional disparity between hemispheres was evaluated based on median and median absolute deviation. Further, patient-level autoregressive integrative moving average models were calculated for each signal stream and used to generate personalized vector autoregressive models. Multi-variate cerebral physiologic relationships between hemispheres were assessed via impulse response functions and Granger causality analyses. Data from 102 healthy control volunteers, 27 spinal surgery patients, and 95 TBI patients (varying in frontal lobe pathology impacting the optode path; 64 without bifrontal lobe pathology, 15 without left frontal lobe pathology, 11 without right frontal lobe pathology, and 5 with bifrontal lobe pathology) were retrospectively analyzed. For subjects with or without cranial pathology, no difference in COx/COx-a was found between hemispheres regardless of the analytic method. In TBI patients without pathology underneath the NIRS sensor, distant parenchymal injury does not seem to have an effect on the CA of uninjured frontal lobes. Further work is required to characterize regional disparities with multi-channel CA measurements in healthy and disease states. Full article

During development, the remodelling of fibrillar components of the uterine extracellular matrix (ECM), mediated by the matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), plays an essential role in embryonic survival. Previously, we observed that in the plains viscacha (Lagostomus maximus), only caudal implantation sites (IS) contain viable embryos, whereas embryos at cranial and middle IS die and are reabsorbed. The objective of this study was to analyse the distribution and expression of key components of the endometrial ECM, including fibrillar collagens, MMPs 2 and 9, and TIMPs 1 and 2, in three uterine segments (US) of the non-pregnant adult viscachas. In sections from three US, we observed a significant craniocaudal increase in collagen fibres (Van Gieson and Picrosirius red staining) and elastic fibres (Verhoeff-Van Gieson trichrome staining), along with the immunolabelling levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 (immunohistochemistry). Zymography revealed similar gelatinolytic activity of MMP-2 in the three US but higher than the MMP-9 activity. However, MMP-9 activity in the caudal segment was significantly higher than that in the cranial and middle ones. These findings suggest that uterine ECM variations along the craniocaudal axis may contribute to uterine remodelling processes that regulate embryonic survival during gestation. Full article

Background: Different lateral and postero-lateral cranial approaches to the petroclival region and to the mid-upper brain stem have been described so far, some of which require extensive osseous demolition and possible damage of neurovascular structures. Neuronavigational systems are now extensively available for preoperative planning and intraoperative navigation to assist the surgeons in choosing the optimally invasive approach for each pathology. Herein, we describe a detailed navigation-augmented morphometric analysis to bring insight into the usefulness of an anterior petrosectomy (AP) to handle lesions in the petroclival region. Methods: Eight cadaveric, silicone injected heads were used. A total of 14 approaches (AP, n = 8; retrosigmoid, RS, n = 6) using a standard microsurgical dissection technique were performed. All specimens had preoperative CT and MRI scans, as well as a post-dissection CT. The neuronavigational system was used for distance measurements, craniotomy sizes and surgical corridor volumes, for each approach. Results: The distance from the skull surface to the petrous apex was significantly shorter in the AP approach when compared with the RS (46.0 ± 1.9 mm versus 71.3 ± 1.8 mm, respectively, p < 0.001). Although the craniotomy size was not different, the volume of the surgical corridor was significantly larger with the AP approach (21.31 ± 1.91 cm³ vs. 13.39 ± 1.8 cm³). The AP approach increased the length of the basilar artery exposure from 6.9 ± 1.5 mm (obtained with a standard subtemporal approach) to 22.1 ± 1.7 mm (p < 0.0001). Conclusions: The surgical corridor to the petroclival region achieved by virtue of an AP was significantly larger and featured shorter working distances, resulting in a higher degree of surgical freedom. Although significant individual anatomical variations of fundamental neurovascular and bony structures were found, these difficulties were overcome by careful pre- and intraoperative use of neuronavigation. Full article

The skull structure in vertebrates is closely related to feeding mode. This study examines the relationship between the cranial joint morphology variation among different lizard species [Eumesces schneideri (Daudin, 1802), Anguis colchica (Nordmann, 1840), and Eremias suphani (Başoğlu & Hellmich 1968)] and their feeding habit. This study investigates the cranial anatomical correlates of distinct cranial kinesis models. Different cranial joints permitting intracranial mobility have been observed among these species using histological section and whole-mount techniques. The cranial joints are similar among species that generally exhibit cranial kinesis. The stomach contents of the species were analyzed, and E. schneideri has the highest prey diversity among the examined species, followed by E. suphani and A. colchica in that order. The study indicated that the prey preferences differ among three lizard species. While no plant material was detected in the stomach contents of E. suphani and E. schneideri, it was detected in A. colchica. The diet of the three lizards consisted of various species of small arthropods such as Arachnida, Lepidoptera, Coleoptera, Formicidae, and Gastropoda. Additionally, no significant differences were detected in SVL, head, and jaw size measurements between adult males and females of each species. Full article

(1) The purpose of this study is to relate the bidimensional and tridimensional measures of the palate to the vertical facial pattern defined by the angle “SN-MP” between the mandibular plane and the anterior cranial base (Sella–Nasion/mandibular plane angle) in skeletal Class II untreated patients. Furthermore, the same palatal measures were used to compare Class II with Class I subjects. (2) A sample of 197 Class II Caucasian subjects (112 females and 85 males) with untreated skeletal Class II was collected retrospectively (from a private dental clinic specialized in orthodontics) and divided into two main groups according to the ANB angle: 74 Class I patients (0° ≤ ANB ≤ 4°) and 123 Class II patients (ANB > 4°). Class II subjects were furthermore divided into three groups depending on the angle SN-MP. Lateral cephalograms and digital 3D maxillary dental scans were available. Bidimensional and tridimensional measures were taken on each maxillary dental scan. The differences among the groups were analyzed for significance using a variance analysis. (3) A decrease in the posterior palatal height and an increase in the palatal surface area in Class I subjects were reported. The results showed a change in upper arch form, with a greater intermolar width in patients with a low SN-MP angle and a smaller one in high-angle patients. The more a Class II subject tended towards high-angle divergence, the narrower the palate was. (4) A greater posterior palatal height was found in Class II malocclusion, while greater surface area was noted in Class I malocclusion. In addition to this result, another statistical significance was detected in Class II malocclusion: the intermolar distance was greater in hypodivergent than in hyperdivergent patients. Similar volume values were noted across different malocclusions and vertical divergence groups. Palatal width seemed to be related to vertical facial pattern, while palatal height and area seemed to be related to sagittal malocclusions. These findings underscore the importance of considering palatal morphology variations in designing individualized orthodontic treatments, thereby improving patient-specific outcomes and broadening our understanding of skeletal Class II malocclusion. Full article