Skulls Research Articles

Treatment envelope of transcranial histotripsy: challenges and strategies to maximize the treatment location profile.

A 750kHz, 360-element ultrasound array has been built for transcranial histotripsy applications. This study aims to evaluate its performance to determine whether this array is adequate for treating a wide range of brain locations through a human skull. Treatment location profiles in 2 excised human skulls were experimentally characterized based on passive cavitation mapping. Full-wave acoustic simulations were performed in 8 human skulls to analyze the ultrasound propagation at shallow targets in skulls with different properties. Results showed that histotripsy successfully generated cavitation from deep to shallow targets within 5 mm from the skull surface in the skull with high SDR and small thickness, whereas in the skull with low SDR and large thickness, the treatment envelope was limited up to 16 mm from the skull surface. Simulation results demonstrated that the treatment envelope was highly dependent on the skull acoustic properties. Pre-focal pressure hotspots were observed in both simulation and experiments when targeting near the skull. For each skull, the acoustic pressure loss increases significantly for shallow targets compared to central targets due to high attenuation, large incident angles, and pre-focal pressure hotspots. Strategies including array design optimization, pose optimization, and amplitude correction, are proposed to broaden the treatment envelope. This study identifies the capabilities and limitations of the 360-element transcranial histotripsy array and suggests strategies for designing the nextgeneration transcranial histotripsy array to expand the treatment location profile for a future clinical trial.&#xD.

Allometry of human calvaria bones during development from birth to 8 years of age shows a nonlinear growth pattern

Pediatric skulls change rapidly in size and shape during development, especially for children up to 8 years of age. This project was developed to address the gap in understanding of the three-dimensional growth parameters of the human skull during this period and the impact these growth patterns have on fontanelle closure and suture formation. This study offers novel data on the dynamic changes in the anatomy of the skull with the intention of providing better guidance for pediatric surgical care. Craniometric landmarks defined on three-dimensional computed tomography reconstructions were used to map skull development in children aged 0 to 8 years old. A total of 364 datasets were analyzed and statistically representative 3D skulls with anatomical craniometric features such as head shape, bone size, suture and fontanelle closure time were generated for 17 age groups spanning birth to 8 years of age to provide a comprehensive neuroanatomical understanding of how the pediatric skull changes over time. This study indicates that the cranial bones follow a non-linear growth pattern, with the occipital and frontal bones driving the directionality of fontanelle closure and delivers a 3D visualization of the developmental characteristics of the skull providing a landmark resource for understanding the growth dynamics of the human skull. While clinical measurements remain valid approaches for the planning of surgical interventions, these 3D models may provide a more accurate planning paradigm.

Comparative analysis of mechanical and drilling properties: Human skull vs. 3D-printed replicas for neurosurgical training

Neurosurgery is one of the most difficult surgical disciplines, making neurosurgical simulation crucial for learners. 3D printing is increasingly used for this simulation due to its accessibility and cost-effectiveness compared to conventional methods. Previous studies have qualitatively evaluated the efficacy of 3D printing models for burr hole and craniotomy simulation using surgeon feedback. This study quantitatively evaluates the mechanical properties of human skulls and compares them with 3D-printed skulls to identify the necessary materials and technologies for accurate replication in neurosurgical training. Vickers hardness, compression, and drilling simulation tests were conducted on human cadaveric skulls and 3D-printed models manufactured using Fused Filament Fabrication (FFF), Stereolithography (SLA), and Material Jetting (MJ) technologies. Uniaxial force during a simulated burr hole procedure was measured as drilling progressed through the outer table (OT), diploë and inner table (IT) of the skull. The results showed that different 3D printing technologies and materials have qualities corresponding to each of the three layers of the human skull. For instance, the White Resin 40 model was the closest match to the OT of human skull, exhibiting the lowest mean difference of drilling modulus of 1.98. The OT of the human skull had a Vickers hardness of 38.6 ± 5 HV0.05. The closest 3D-printed models were SLA White at 16.6 ± 0.3 HV0.05 and Rigid 10K at 65.7 ± 3 HV0.05. In terms of mechanical properties, the human skull demonstrated a compression modulus that closely matched the SkullSTN 2, PC 60, PEEK 40, and PEEK 60, with differences of less than 0.1 GPa. These findings demonstrate the effectiveness of drilling simulation tests in evaluating various materials and infills to refine models before neurosurgeon evaluation, enabling the identification of an optimal 3D-printed training model for simulating burr hole procedures.

Enhancing sports mouthguards with PLA + and PC: stress reduction, energy absorption, and topology optimization.

The objective of this paper was to compare the effectiveness of different materials for mouthguards in preventing oral and maxillofacial injuries during sports activities. The present study compares the stress-reduction and energy absorption capabilities of two other fused filament materials - poly(lactic-acid plus) (PLA+) and polycarbonate (PC), with Ethylene-vinyl acetate (EVA), which is the most commonly used material for mouthguard fabrication. Two human skulls were modelled, and a boxing glove simulated punches along the x, y, and z-axes with 5mm displacement with 1 kN force. Firstly, the maximum principal stress curve in the skull was compared for forces along the three perpendicular directions. Furthermore, the present study examines materials energy absorption properties, including their specific energy absorption characteristics and initial peak von Mises stresses. Additionally, a topology optimization approach is used to create an alternative design for a mouthguard to improve specific energy absorption. The model without a mouthguard showed the highest stress concentration of 32.298MPa in the teeth, followed by the EVA material, which resulted in a maximum principal stress of 28.525MPa. Fused filament 3D materials, such as PLA + and PC, on the other hand, showed better mechanical effectiveness in both lower jaw dislocation and lower maximum principal stress by 30.82% and 51.25% in the mandibular and maxillary teeth. Though EVA comparatively shows better specific energy absorption capability at 2.24kJ/kg post-optimization than PLA + and PC, the peak principal stress experienced in the mandibular region was comparatively higher. The topology optimization, however, improved the energy-absorbing capabilities of PLA + by 4.5 times, reaching 1.37kJ/kg and PC from 0.165kJ/kg to 0.38kJ/kg. This study demonstrates that PLA + and PC have better stress reduction capabilities than EVA and could be promising materials for the fabrication of mouthguards in sports activities. This study highlights the importance of topology optimization in dental materials science and engineering to develop safer and more effective mouthguard designs.

Micro-XCT analysis of anatomical features and dimensions of the incisive canal: implications for dental implant treatment in the anterior maxilla

BackgroundThis study used micro-focus X-ray Computed Tomography (micro-XCT) to examine the anatomical differences and dimensions of the maxillary incisive canal (MIC) in a South African population. The accurate imaging yielded dependable results that support earlier research and enhance anterior maxilla surgery planning. Furthermore, these anatomical features are compared between various racial and gender groupings in the study.MethodsUsing a micro-XCT scanner, 108 human cadaver skulls from the Pretoria Bone Collection were scanned and included in the study. Advanced volume rendering software was employed for measuring the MIC length, diameter, shape, and the buccal bone wall measurements in relation to the MIC.ResultsSignificant anatomical variation in the size and shape of the MIC was identified in the population, with variations seen between racial and gender groups. The incisive foramen (ICO) mean diameter was 6.61 mm, and the MIC length varied from 4.96 to 20.10 mm. There were significant differences in the buccal alveolar bone height between different ethnic groups and gender. Regarding morphological patterns in coronal and sagittal views, single canals were more common in the black population while Y-shaped canals were more common in the white population. The study also introduced a new metric by measuring the mean distances between teeth #11 and #21 and the ICO (1.83 mm and 1.88 mm respectively).ConclusionsThe complex anatomical differences of the MIC in a South African population were clarified. Clinicians should be aware of tooth sockets in near proximity to the MIC and perform accurate preoperative assessment using sophisticated 3-D imaging and preferable guided implant placement in the anterior maxilla.

P09.02.A A WINDOW TO THE BRAIN: MONITORING THE HUMAN BRAIN USING FUNCTIONAL ULTRASOUND (FUS)-IMAGING IN FREELY MOVING SUBJECTS WITH AN ACOUSTICALLY FAVORABLE SKULL IMPLANT

Abstract BACKGROUND To this day, the mainstay of human neuroimaging remains (functional) Magnetic Resonance Imaging (fMRI), where subjects are asked to lie completely still and silent in a noisy scanner. Many key questions in clinical care and neuroscience remain poorly studied because of fMRI’s inability to facilitate natural behavior such as locomotion or even verbal speech. What is more, due to the cost and size of an (f)MRI-machine, monitoring of morphological (i.e. tumor regrowth) or functional changes in the human brain, pre- and post-tumor resection, is often spread out over intervals of many months, leaving patients in suspense about possible tumor regrowth.With the advent of ultrafast ultrasound imaging, a new high-resolution, depth-resolved and mobile neuro-imaging technique called functional Ultrasound (fUS) has emerged. In the last decade, fUS has been applied successfully in awake neurosurgical contexts to map out hemodynamics-based functional brain activity as well as tumor tissue at a mesoscopic scale. However, given the significant aberration of ultrasound signal through human skull bone, fUS is not available outside of OR as of yet. As a first step outside of the OR, we aimed to apply fUS in freely moving subjects with a skull bone defect covered by PEEK, an acoustically favorable material. MATERIAL AND METHODS Two subjects with PEEK-implants were repeatedly imaged over a period of >1 year. One of the subjects received a PEEK-implant after infection of the autologous bone, post-resection of an astrocytoma. Each subject received a custom-fitted 3D-printed helmet based on their MRI to fixate the probe and to attach the geometry needed for optical tracking. Using an optical tracking camera, the position of the Power Doppler Image (PDI) relative to CT/(f)MRI-volumes of the subject could be determined in real-time. Images were acquired using an experimental research system (Vantage-256, Verasonics) interfaced with a 9L-D linear array (GE, 5.3 MHz). All scans were acquired with a PRF of 800 Hz. The PDIs and angle compounded beamformed frames were stored for offline processing, consisting of 3D-vascular reconstructions and functional mapping. Functional tasks focused on the sensorimotor area of the lip. For measurements outside of the lab, the acquisition system was transformed into a mobile cart, which could be pushed by the subject itself. RESULTS Trans-PEEK imaging resulted in PDIs with highly detailed vasculature of healthy brain tissue and the resection cavity, up to several centimeters in-depth, reproduced reliably over a period of >12 months. In sedentary, standing and walking conditions, we were able to produce consistent functional maps of the human brain. CONCLUSION Our current work demonstrates how fUS has the potential to become a powerful window to the brain, both in terms of vascular monitoring of tumor regrowth, as well as functional brain mapping, outside of the operating room.

Biomechanical evaluation of six zygomatic implants versus four zygomatic implants combined with dental implants in the treatment of different maxillary defects

BackgroundThis study aims to compare the biomechanics of six zygomatic implants (ZIs) and dental implants (DIs) combined with four ZIs with different maxilla defects.MethodsThree-dimensional constructs of the ZIs, DIs human skulls, and maxillary prostheses were created using SolidWorks Software (Version 2015, Dassault Systems SolidWorks Corporation, Waltham, MA, USA). Eight finite element models of the skull with four different alveolar defect types (0–4) were constructed. Type 0: No defect; Type 1: Bilateral posterior defects; Type 2: Right posterior defect; Type 3: Anterior and left posterior defects; Type 4: Bilateral posterior and anterior defects. In two models with the same defect type (for defect types 0–2), six ZIs or two DIs combined with four ZIs were inserted into the maxilla. Six ZIs were inserted in the maxilla models with defect types 3 and 4. Vertical (150 N) and masseteric (300 N) loads were simulated on the prosthesis. The maximum Von Mises stress in the implants/surrounding bone and bone deformation were evaluated.ResultsThe maximum Von Mises stresses in bone/implant were found highest in the defect type 2 model with four ZIs combined with two DIs. The lowest maximum Von Mises stress for bone was detected in the model with defect type 0 and with six ZIs.ConclusionAmong the four types of defects, the posterior unilateral defect caused the highest stress value.

Morphometric study of foramen magnum and its correlation with cranial morphometry in dry human skulls of north India

Morphometric study of foramen magnum and its correlation with cranial morphometry in dry human skulls of north India

Cranial anatomy of Bagualia alba (Dinosauria, Eusauropoda) from the Early Jurassic of Patagonia and the implications for sauropod cranial evolution

Sauropods are the largest terrestrial vertebrates ever known. During their evolution, they underwent numerous morphological changes, some of which occurred at the end of the Early Jurassic. However, current knowledge of Early Jurassic dinosaurs is scarce, especially cranial information. Here we describe the skull of the basal eusauropod Bagualia alba from the Cañadón Asfalto Formation (Toarcian; Early Jurassic) of Patagonia, Argentina, which represents the most complete eusauropod skull from the late Early Jurassic worldwide. The osteological description and phylogenetic relationships of Bagualia allowed us to determine the acquisition of the common cranial bauplan of eusauropods at the end of the Early Jurassic: a tall and robust rostrum with great retraction of the external nares; a deep narial fossa; a reduced antorbital fenestra; verticalization of the lacrimal; prefrontal without an anterior process; anteroposterior shortening of the frontal; a supratemporal fenestra visible laterally; a robust braincase; ‘U’-shaped jaws in dorsal view; reduction in the number of teeth in the dentary; teeth with crown to crown occlusion; development of lateral plates in the premaxilla and maxilla; and a dorsoventral expansion of the dentary symphysis. These cranial characteristics were recently suggested to be related to a change in the diet of the sauropods toward mainly hard vegetation. In this context, Bagualia contributes to filling a gap in cranial evolution between the gracile skulls of Sauropodiformes and the highly robust skulls widely represented in Middle Jurassic taxa.

Alteration by natural processes or anthropogenic manipulation? Assessing human skull breakage through machine learning algorithms

Bone breakage is one of the most common features in the archaeological record. Fractures occur at different times and are classified as fresh or dry depending on the presence or absence of collagen in the bone. In the study of human remains, the timing of the occurrence of a fracture is of crucial importance as it can sometimes be linked to the cause of death. Types of skull breakage can be classified based on when they occurred, though not all fractures correspond to the expected features. This variability is added to the challenge of working with bones covered in consolidant, which obstructs the bone surface and hinders taphonomic analysis. This is the case of the Txispiri calotte, which was categorized as a skull cup in the early 20th century, though this classification was later rejected in the 1990s. In this study, we used statistics and machine learning (ML) to test the breakage characteristics of one set of skull fragments with fresh fractures, another set with dry fractures, and the Txispiri calotte. For this purpose, we considered the fracture type, trajectory, angles, cortical delamination and texture of each of the individual fractures. Our results show that the 13 fractures of the Txispiri calotte correspond to dry breakage and bear no relation to artificially produced skull cups. This study shows the potential of ML algorithms to classify fresh and dry fractures within the same specimen, a method that can be applied to other assemblages with similar characteristics.

No birth-associated maternal mortality in Japanese macaques (Macaca fuscata) despite giving birth to large-headed neonates

Human fetuses at term are large relative to the dimensions of the maternal birth canal, implying that their birth can be associated with difficulties. The tight passage through the human birth canal can lead to devastating outcomes if birth becomes obstructed, including maternal and fetal death. Although macaques have to accommodate similarly large fetuses, relative to their maternal birth canals, it was not known whether macaque mothers face birth difficulties similar to humans. Based on 27 y of demographic data from a semi-free-ranging, closely monitored population of Japanese macaques (Macaca fuscata), we found no birth-associated mortality in macaques. This differs from the situation in many human populations. We suggest three nonmutually exclusive hypotheses to explain these observations. i) The macaque fetal skull is similarly flexible as the human fetal skull. ii) The macaque pelvis and connective tissue show greater flexibility during birth. iii) The interplay between macaque pelvic shape and birth dynamics is smoother and incurs fewer complications than in humans.

Modelling Mucus Clearance in Sinuses: Thin-Film Flow Inside a Fluid-Producing Cavity Lined with an Active Surface

The paranasal sinuses are a group of hollow spaces within the human skull, surrounding the nose. They are lined with an epithelium that contains mucus-producing cells and tiny hairlike active appendages called cilia. The cilia beat constantly to sweep mucus out of the sinus into the nasal cavity, thus maintaining a clean mucus layer within the sinuses. This process, called mucociliary clearance, is essential for a healthy nasal environment and disruption in mucus clearance leads to diseases such as chronic rhinosinusitis, specifically in the maxillary sinuses, which are the largest of the paranasal sinuses. We present here a continuum mathematical model of mucociliary clearance inside the human maxillary sinus. Using a combination of analysis and computations, we study the flow of a thin fluid film inside a fluid-producing cavity lined with an active surface: fluid is continuously produced by a wall-normal flux in the cavity and then is swept out, against gravity, due to an effective tangential flow induced by the cilia. We show that a steady layer of mucus develops over the cavity surface only when the rate of ciliary clearance exceeds a threshold, which itself depends on the rate of mucus production. We then use a scaling analysis, which highlights the competition between gravitational retention and cilia-driven drainage of mucus, to rationalise our computational results. We discuss the biological relevance of our findings, noting that measurements of mucus production and clearance rates in healthy sinuses fall within our predicted regime of steady-state mucus layer development.

Advancing 3-Dimensional Printed Burr Hole and Craniotomy Models for Neurosurgical Simulation Through Multimaterial Methods

Objective3D printing technology presents a promising avenue for the development of affordable neurosurgical simulation models, addressing many challenges related to the use of cadavers, animal models, and direct patient engagement. The aim of this study is to introduce and evaluate a new high-fidelity neurosurgical simulation model targeted for both burr hole and craniotomy procedures. MethodsTwelve different 3D printed skull models were manufactured using five different materials (PEEK, White Resin, Rigid10K, BoneSTN, SkullSTN) from three different 3D print processes (Fused Filament Fabrication, Stereolithography, Material Jetting). Six consultant neurosurgeons conducted burr holes and craniotomies on each sample while blinded to these manufacturing details. Participants completed a survey based on the qualities of the models, including; mechanical performance, visual appearance, interior feeling, exterior feeling, sound, overall quality, and recommendations for training purposes based on their prior experience completing these procedures on human skulls. ResultsThis study found that the multi-material stereolithography printed models consisting of White Resin for the outer table and Rigid 10K for the diploe and inner table were successful in replicating a human skull for burr hole and craniotomy simulation. This was followed by the porous General BoneSTN preset material on a Stratasys J750 Digital Anatomy Printer. ConclusionsThe findings indicate that widely accessible and economical desktop stereolithography 3D printers can provide an effective solution in neurosurgical training, thus promoting their integration in hospitals.

The size and shape of the pterygomaxillary fossa of the human skull during the period of formed primary dentition (based on the analysis of CT scans)

Abstract Relevance. This work is relevant due to the fact that the pterygomaxillary fossa (PMF) and the underlying pterygopalatine ganglion (PPG) attract the attention of clinicians developing surgical accesses to this ganglion. Currently, there is no detailed description of the size and shape of the PMF in children during the period of formed primary occlusion. The aim is to study the size and shape of the PMF on the basis of computed tomography during the period of formed primary occlusion. Materials and methods. To study the size and shape of the PMF, the analysis of frontal and axial CT scans of 12 children (24 CT scans) aged 3.5–4.5 years was carried out. On the basis of these data, a three-dimensional reconstruction of the PMF was created. Results. Four parts were distinguished in the PMF: the main one adjacent to the sphenopalatine foramen (SPF), and funnel-shaped constrictions: the vestibule of the pterygoid canal, the vestibule of the greater palatine canal and the vestibule of the pterygomaxillary fissure. It is suggested that the PPG lies in the vestibule of the pterygoid canal. Data on the main dimensions of the PMF were also obtained. Conclusion. PMF in children aged 3.5–4.5 years is characterized by a complex structure of the cavity, suggesting a different position of the PPG in it than is commonly believed. This circumstance, as well as for the first time the sizes of the PMF determined by us, should be taken into account when developing surgical access to the PMF and the PPG.

Laser Scanning Morphometric Measurements of the Main Orbital Communications in Dry Human Skulls

Background and Objectives: This research investigated the morphometric dimensions of the optic foramen (OF), superior orbital fissure (SOF) and inferior orbital fissure (IOF), using indirect measurement techniques such as laser scanning, making it likely the first study of its kind. This study aimed to identify the morphometric variability of the main orbit communications and to highlight the differences between genders. Materials and Methods: The anthropometric study was conducted on sixty dry skulls (120 orbits) of adults aged between 20 and 70 years. Measurements of orbital communications were made using the RS6 laser scanner. The orbital parameters that were investigated are as follows: length and width of the SOF and IOF, and height and width of the OF. Results: In males, the average height of the OF was 8.27 mm and 8.13 mm in females, while the average width of the OF was 6.34 mm in males and 5.83 mm in females. The SOF average length was 21.09 mm in males and 17.58 mm in females. The widths of the SOF in the three thirds (anterior, middle and posterior) in males were 5.14/4.77/7.11 mm and 2.28/3.48/5.80 mm in females. The average length of the IOF was 33.05 mm in males and 32.30 mm in females. The widths of the IOF in the three thirds (anterior, middle and posterior) were 5.61/3.92/4.70 mm in males and 7.24/4.68/4.08 mm in females. Conclusions: The OF height and width were higher in males compared to females. The SOF length and width were higher in males compared to females. The IOF length was higher in males for the right orbit and higher in females for the left orbit. The IOF width for both orbits was higher in females in the anterior and middle third, and higher for males in the posterior third. Evaluation of dry skulls using laser scanning is reliable and recommended for data accuracy. Laser scanning can become a usable method for all indented and hard-to-reach regions of the cranial skeleton.

3D model related to the publication: Cranial Anatomy of Indohyus indirae (Raoellidae), an artiodactyl from the Eocene of India, and its implications for raoellid biology

3D model related to the publication: Cranial Anatomy of Indohyus indirae (Raoellidae), an artiodactyl from the Eocene of India, and its implications for raoellid biology

Improved Quantification of MicroPET/CT Imaging Using CT-derived Scaling Factors.

Combined micro-PET/CT scanners are widely employed to investigate models of brain disorders in rodents using PET-based coregistration. We examined if CT-based coregistration could improve estimates of brain dimensions and consequently estimates of nondisplaceable binding potential (BPND) in rodent PET studies. PET and CT scans were acquired on 5 female and 5 male CD-1 mice with 3-[18F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([18F]FPEB), a radiotracer for the metabotropic glutamate receptor subtype 5 (mGluR5). In the proposed PET/CT (PTCT) approach, the tracer-specific standard volume was dimension-customized to each animal using the scaling factors from CT-to-standard CT coregistration to simplify PET-to-standard PET coregistration (i.e., 3 CT- and 6 PET-derived parameters). For comparison, conventional PET-based coregistration was performed with 9 (PT9) or 12 (PT12) parameters. PET frames were transferred to the standard space by the three approaches (PTCT, PT9, and PT12) to obtain regional time-activity curves (TACs) and BPND in 14 standard volumes of interest (VOIs). Lastly, CT images of the animals were transferred to the standard space by CT-based parameters from PTCT and with the scaling factors replaced with those from PET-based PT9 to evaluate agreement of the skull to the standard CT. The PET-based approaches showed various degrees of underestimations of scaling factors in the posterior-anterior-direction compared to PTCT, which resulted in negatively proportional overestimation of radioactivity in the cerebellum (reference region) up to 20%, and proportional, more prominent underestimation of BPND in target regions down to -50%. The skulls of individual animals agreed with the standard skull for scaling factors from PTCT but not for the scaling factors from PT9, which suggested inaccuracy of the latter. The results indicated that conventional PET-based coregistration approaches could yield biased estimates of BPND in proportion to errors of brain dimensions when applied to tracers for which the cerebellum serves as reference region. The proposed PTCT provides evidence of a quantitative improvement over PET-based approaches for brain studies using micro-PET/CT scanners.

Numerical and Experimental Validation for Connecting Nature with Architecture by Mimicking Cranium into a Shell Roof

This study focuses on a structural element bio-mimicked from the human cranium (HC) into a shell element. As the HC is effective in resisting intracranial pressure developed by the brain, a water tank was considered to use a bio-mimicked shape of a shell as a roof. An optimized numerical model was validated experimentally and compared with a conventional specimen. The structural behavior of the bio-mimicked specimen is similar and performs more efficiently than the conventional specimen in capacity ratio, crack formation, and load-carrying capacity. Methodology followed: A Computed Tomography (CT) scan of the HC was obtained in Digital Imaging and Communications in Medicine (DICOM) format for finite element analysis (FEA). From the geometric parameters of the HC, the radius of the curvature-to-thickness ratio was derived for the shell. The span and thickness of the shell under two criteria were considered. The spherical and circular shell behaviors were found to be similar to those of the HC, whereas the elliptical shell behavior was not. We studied the shape effect of the HC with the conventional slab and found that the HC shape has an impact on the behavior and is the most efficient. A bio-mimicked mono column was considered as a supporting column for the water tank and analyzed. Overall, adopting this bio-mimicking of the HC into the shell roof connects nature with sustainable architecture.

Zygomaticofacial foramen in dry adult human skulls: a morphological study.

A wide range of medical procedures in the zygomatic region in maxillofacial surgery, implantology, and aesthetic medicine requires a detailed study of the zygomaticofacial foramen (ZFF) due to the high risk of damage to its contents during manipulation.This study aimed to estimate the shape, diameter, and location of ZFF and their relationships with anatomical landmarks. A studywas conductedon 53 dry adult human skulls. Standard morphometric measurementswere takenusing sliding calipers.The number, diameter, shape, and location of ZFF were notedon both sides, andthe distances between the ZFF and surrounding anatomical landmarks were measured.Conventional statistical methods were usedto evaluate the data. Out of 106 sides, no ZFFwas noticedin 2.8%, one foramen was found in 40.6%, two foramina were found in 39.6%, threein 10.4%, four in 4.7%, andfive in 1.9%. The vertical diameter was 0.98 ± 0.35 mm, while the transverse diameter was 0.87 ± 0.31 mm. The shape of the ZFF was oval in 67%, round in 26.2%, semilunar in 4.9%, and irregular in 1.9%. The distance from the ZFF to the infraorbital margin was 6.63 ± 2.09 mm, tothe frontozygomatic suture was 26.24 ± 3.49 mm, tothe zygomaticomaxillarysuture,was 19.75 ± 3.55 mm, tothe zygomaticotemporal suture was 22.31 ± 3.98 mm and, to the most prominent point of the zygomatic bone was 8.03 ± 2.64 mm. The variations in the number and location of ZFF mustbe consideredwhile performing regional blockanesthesia,and surgical or aesthetic procedures in the zygomatic region.

Sex estimation based on glabella morphology in contemporary Brazilian human skulls

BackgroundEstimating sex from a dry skull depends on studying validated and specific traits. One such reference area exhibiting sexual dimorphism is the glabella, located on the frontal bone. This anatomical landmark is easily classified and shows promising results in sexual identification due to its magnitude variations between sexes. The present study is methodologically based on Walker’s approach, which visually analyzes cranial traits and scores them according to their morphology. This study aimed to investigate the sex estimation of dry skulls from Brazilian human skeletons for human identification through macroscopic analysis of the glabella. This analytical, quantitative, cross-sectional study utilized a sample of 471 skulls from both sexes, aged 25 years or older, belonging to the contemporary collection of the Center for Studies in Forensic Anthropology at the Faculty of Dentistry, University of Pernambuco (CEAF/FOP/UPE), Brazil. Data were recorded in an Excel spreadsheet and subsequently subjected to statistical analysis using IBM© SPSS (version 22.0).ResultsInitial observation of the skeletons excluded 52 (11.0%) due to age below 25 years, absence of a skull, or compromised glabella region, resulting in a final sample of 419 skulls. The mean age was 66.6 years, with a median of 67, a minimum of 25, and a maximum of 109 years. Regarding glabella types, score 2 showed the highest frequency (35.6%), while score 5 had the lowest percentage (7.9%). A statistically significant association was found between female sex and glabella scores 1 and 2. Also, individuals aged over 60 presented more glabella scores 1 and 2. The sex estimation accuracy for the sample was 76.1%, with females having a higher percentage of correct observations than males.ConclusionsThe morphology of the glabella provides useful information for estimating sex in the biological profile. However, further studies on this morphological trait in other Brazilian osteological collections are encouraged to establish a national profile and contribute to human identification procedures in the country.