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Medical Principles and Practice :... 2022Luckenschadel skull is a skull that is radiologically characterized by lacunae in the cranial vault. To date, although the association between neurological abnormalities...
OBJECTIVE
Luckenschadel skull is a skull that is radiologically characterized by lacunae in the cranial vault. To date, although the association between neurological abnormalities and scoliosis is well recognized, no relationship between idiopathic scoliosis and a lacunar skull has been defined. We explored the incidence and time courses of lacunar skulls in patients with idiopathic scoliosis.
MATERIALS AND METHODS
Spinal X-rays of 3,170 children aged 6-16 years with idiopathic scoliosis evaluated from October 2010 to August 2020 were examined for the presence of an irregular inner calvarial table indicative of a Luckenschadel skull. A total of 1,760 (55.5%) of the 3,170 images included the skull. We also explored the frequency of intraspinal abnormalities in children with lacunar skull images who underwent spinal magnetic resonance imaging.
RESULTS
The study population consisted of 1,760 children, 1,203 girls (68.4%) and 557 (31.6%) boys. A total of 268 (15.2%) clearly evidenced lacunar skulls in their radiographs; 186 (69.4%) girls (11.3 ± 4.3 years) and 82 (30.6%) boys (12.6 ± 3.3 years). Two of the 56 patients (3.6%) who underwent spinal MRI had intraspinal abnormalities (isolated Chiari malformation-I). No additional neurological problems were detected in children with lacunar skulls.
CONCLUSION
We conclude that the lacunar skull is very common in children with idiopathic scoliosis who lack any other neurological pathology. The lacunar skull does not disappear even in adolescence. Although previous publications have stated that lacunar skull disappears over time in radiographic images, we observed that it became more noticeable over time in children with scoliosis.
Topics: Adolescent; Arnold-Chiari Malformation; Child; Female; Humans; Incidence; Magnetic Resonance Imaging; Male; Scoliosis; Skull
PubMed: 34875653
DOI: 10.1159/000521359 -
Open Veterinary Journal 2022The sutures are associated with anatomical and physiological differences in skull camels. There is a deficiency in the information regarding the anatomy of dromedary...
OBJECTIVE
The sutures are associated with anatomical and physiological differences in skull camels. There is a deficiency in the information regarding the anatomy of dromedary camels, especially on fibrous joints (sutures) of the camels' skull.
AIM
The goal of this work was to give a detailed gross anatomical and radiographic description of the sutures in the camels' skull. This description may be of great importance for veterinarians to differentiate between the suture and the fracture of the head in the radiographic photos.
METHODS
The current study was conducted on 10 skulls of the young (Howar) dromedary camel at 4-10 months old. The skulls were prepared by using the boiling and maceration techniques. The gross and radiographic photos of the sutures were taken using a digital camera and Siemens mobile full-wave X-ray machine (Siemens Medical Solutions, Erlangen, Germany).
RESULTS
The skull is made up of nineteen bones -6 single and 13 paired-the majority of which are joined by joints termed as sutures. The sutures of the camel skulls were viewed in dorsal, ventral, lateral-vertical, and inside directions. They were of four types which are the coronal, serrate, plane, and squamosal sutures in different positions of the skull.
CONCLUSION
The current study showed that the fibrous joints of camel skulls (sutures) were similar to those of other domestic animals. This information is critical for supporting veterinarians to differentiate sutures from fractures that may have happened in the skull of the dromedary camel using radiological pictures.
Topics: Animals; Camelus; Skull; Animals, Domestic
PubMed: 36589401
DOI: 10.5455/OVJ.2022.v12.i5.17 -
Ultrasonics Feb 2022Transcranial ultrasound is emerging as a noninvasive tool for targeted treatments of brain disorders. Transcranial ultrasound has been used for remotely mediated...
Transcranial ultrasound is emerging as a noninvasive tool for targeted treatments of brain disorders. Transcranial ultrasound has been used for remotely mediated surgeries, transient opening of the blood-brain barrier, local drug delivery, and neuromodulation. However, all applications have been limited by the severe attenuation and phase distortion of ultrasound by the skull. Here, we characterized the dependence of the aberrations on specific anatomical segments of the skull. In particular, we measured ultrasound propagation properties throughout the perimeter of intact human skulls at 500 kHz. We found that the parietal bone provides substantially higher transmission (average pressure transmission 31 ± 7%) and smaller phase distortion (242 ± 44 degrees) than frontal (13 ± 2%, 425 ± 47 degrees) and occipital bone regions (16 ± 4%, 416 ± 35 degrees). In addition, we found that across skull regions, transmission strongly anti-correlated (R=-0.79) and phase distortion correlated (R=0.85) with skull thickness. This information guides the design, positioning, and skull correction functionality of next-generation devices for effective, safe, and reproducible transcranial focused ultrasound therapies.
Topics: Acoustics; Aged; Aged, 80 and over; Female; Humans; In Vitro Techniques; Male; Middle Aged; Skull; Ultrasonography, Doppler, Transcranial
PubMed: 34717144
DOI: 10.1016/j.ultras.2021.106591 -
IEEE Transactions on Ultrasonics,... Sep 2021Histotripsy has been previously shown to treat a wide range of locations through excised human skulls in vitro. In this article, a transcranial magnetic resonance...
Histotripsy has been previously shown to treat a wide range of locations through excised human skulls in vitro. In this article, a transcranial magnetic resonance (MR)-guided histotripsy (tcMRgHt) system was developed, characterized, and tested in the in vivo pig brain through an excised human skull. A 700-kHz, 128-element MR-compatible phased-array ultrasound transducer with a focal depth of 15 cm was designed and fabricated in-house. Support structures were also constructed to facilitate transcranial treatment. The tcMRgHt array was acoustically characterized with a peak negative pressure up to 137 MPa in free field, 72 MPa through an excised human skull with aberration correction, and 48.4 MPa without aberration correction. The electronic focal steering range through the skull was 33.5 mm laterally and 50 mm axially, where a peak negative pressure above the 26-MPa cavitation intrinsic threshold can be achieved. The MR compatibility of the tcMRgHt system was assessed quantitatively using SNR, B0 field map, and B1 field map in a clinical 3T magnetic resonance imaging (MRI) scanner. Transcranial treatment using electronic focal steering was validated in red blood cell phantoms and in vivo pig brain through an excised human skull. In two pigs, targeted cerebral tissue was successfully treated through the human skull as confirmed by MRI. Excessive bleeding or edema was not observed in the peri-target zones by the time of pig euthanasia. These results demonstrated the feasibility of using this preclinical tcMRgHt system for in vivo transcranial treatment in a swine model.
Topics: Animals; Brain; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Phantoms, Imaging; Skull; Swine
PubMed: 33755563
DOI: 10.1109/TUFFC.2021.3068113 -
ENeuro 2022Intracranial neurophysiological recordings require chronic implants to provide transcranial access to the brain. Especially in larger animals, which participate in...
Intracranial neurophysiological recordings require chronic implants to provide transcranial access to the brain. Especially in larger animals, which participate in experiments over extended periods of time, implants should match the skull curvature to promote osseointegration and avoid tissue and bacterial ingress over time. Proposed CAD methods for designing implants to date have focused on naive animals with continuous and even skull surfaces and calculate Boolean differences between implant and skull surface to fit the implant to the skull curvature. However, custom-fitting by calculating the difference fails, if a discontinuous skull surface needs to be matched. Also, the difference method does not allow designs with constant material thickness along the skull curvature, e.g., to allow fixed screw lengths. We present a universal step-by-step guide for custom-fitting implants which overcomes these limitations. It is suited for unusual skull conditions, like surface discontinuities or irregularities and includes virtual bending as a process to match skull surfaces while maintaining implant thickness. We demonstrate its applicability for a wide spectrum of scenarios, ranging from complex-shaped single-pieced implants to detailed multicomponent implant systems built on even or discontinuous skull. The guide uses only a few software tools and the final virtual product can be manufactured using CNC milling or 3D printing. A detailed description of this process is available on GitHub including step-by-step video instructions suitable for users without any prior knowledge in CAD programming. We report the experience with these implants over several years in 11 rhesus monkeys.
Topics: Animals; Brain; Head; Printing, Three-Dimensional; Prostheses and Implants; Skull
PubMed: 35641225
DOI: 10.1523/ENEURO.0028-22.2022 -
Folia Morphologica 2022The skull is an important anatomical structure to discern dog breeds and wolves from dogs. For this purpose, skull morphology and some morphometric measurements of...
BACKGROUND
The skull is an important anatomical structure to discern dog breeds and wolves from dogs. For this purpose, skull morphology and some morphometric measurements of Malakli dogs, a local breed in the Aksaray region, were examined.
MATERIALS AND METHODS
Thirty-two distances were measured and seven ratios calculated in nine skulls of adult dogs. In our study, different morphological features and statistical findings that were not revealed by taking measurements from 32 distinct anatomical points of Aksaray Malakli dog skull bones were determined in accordance with the literature.
RESULTS
Processus zygomaticus was found to be long and pointed in the Aksaray Malakli dogs. The results of morphometric analysis were as follows: facial index value 107.68 ± 4.98, nasal index value 19.61 ± 3.25, cranial index value 56.17 ± 2.52, basal index value 30.57 ± 1.30, skull index 54.68 ± 3.01, palatal index I value 56.76 ± 1.89 and palatal index II value 59.83 ± 2.23.
CONCLUSIONS
It can be concluded form the present investigation that the neurocranium length, facial index, cranial index, basal index, skull index, and palatal index values were statistically different from other dog breeds.
Topics: Animals; Dogs; Face; Skull; Wolves
PubMed: 33577078
DOI: 10.5603/FM.a2021.0011 -
Scientific Reports Sep 2020Comparative anatomy studies of the skull of archosaurs provide insights on the mechanisms of evolution for the morphologically and functionally diverse species of...
Comparative anatomy studies of the skull of archosaurs provide insights on the mechanisms of evolution for the morphologically and functionally diverse species of crocodiles and birds. One of the key attributes of skull evolution is the anatomical changes associated with the physical arrangement of cranial bones. Here, we compare the changes in anatomical organization and modularity of the skull of extinct and extant archosaurs using an Anatomical Network Analysis approach. We show that the number of bones, their topological arrangement, and modular organization can discriminate birds from non-avian dinosaurs, and crurotarsans. We could also discriminate extant taxa from extinct species when adult birds were included. By comparing within the same framework, juveniles and adults for crown birds and alligator (Alligator mississippiensis), we find that adult and juvenile alligator skulls are topologically similar, whereas juvenile bird skulls have a morphological complexity and anisomerism more similar to those of non-avian dinosaurs and crurotarsans than of their own adult forms. Clade-specific ontogenetic differences in skull organization, such as extensive postnatal fusion of cranial bones in crown birds, can explain this pattern. The fact that juvenile and adult skulls in birds do share a similar anatomical integration suggests the presence of a specific constraint to their ontogenetic growth.
Topics: Alligators and Crocodiles; Anatomy, Comparative; Animals; Biological Evolution; Birds; Dinosaurs; Extinction, Biological; Fossils; Phylogeny; Skull
PubMed: 32999389
DOI: 10.1038/s41598-020-73083-3 -
Threshold of the skull injury for blunt force impacts under free and constraint boundary conditions.International Journal of Legal Medicine Mar 2020The formation of skull fractures is an important topic in legal medicine. In particular, the influence of boundary conditions is controversially discussed in the...
The formation of skull fractures is an important topic in legal medicine. In particular, the influence of boundary conditions is controversially discussed in the literature. A study focusing solely on this aspect was missing. This study aimed to investigate the influence of boundary conditions on the energy threshold for head fractures. Because of the great variability of biological tissue of real skulls, we opted for a head model made from a polyurethane sphere filled with gelatin. Furthermore, we decided to investigate two opposite situations: A fixed configuration where a model was placed on a rigid surface and a (quasi) free boundary configuration where the head model was held at a force of 5 N compensating for gravity. For both configurations, we determined the acceleration signal of the impactor, the force, and the energy threshold for head fracture. It turned out that the fracture forces for both configurations were the same whereas the energy threshold was 11.0 J for the fixed and 13.6 J for the free boundary. The difference seems to be negligible if compared to the effect of varying structural mechanical properties of real human heads. This means that in a forensic case, the two situations most probably cannot be distinguished. To investigate the influence of the impactor mass, we developed a mathematical model and fitted the experimental data. As a result, we found that in the free configuration, a larger mass increases the energy threshold for head fracture. So that in principle, the two configurations are distinguishable.
Topics: Acceleration; Biomechanical Phenomena; Forensic Pathology; Gravitation; Head Injuries, Closed; Humans; Models, Anatomic; Models, Theoretical; Reproducibility of Results; Skull; Skull Fractures
PubMed: 30891630
DOI: 10.1007/s00414-019-02023-2 -
BioMed Research International 2020Skeleton models are important in facilitating a student's easy retention and recollection of information in the future. These may assist students carry out hands-on... (Comparative Study)
Comparative Study
Skeleton models are important in facilitating a student's easy retention and recollection of information in the future. These may assist students carry out hands-on practice in order to acquire and practice new skills that are relevant to first aid. The increasing number of medical institutions and medical students attracts the challenge of inadequate facilitation of the teaching and learning processes. This warrants a study and/or an exploration of an alternative solution such as wooden models in order to solve the problem of scarce and ethically restricted human teaching aids. Wooden pieces (50 cm length × 20 cm diameter) from a tree were prepared for the carving process, and wooden replicas of human skulls were made. Two experimental groups of randomly selected medical students (60: active and 60: control) were separately taught using wooden and natural skull models, respectively. The two groups were assessed and evaluated using the natural skull models to compare their understanding of the anatomy of the skull. Additionally, opinion statements were collected from participants in the active group during the oral examination. Six (6) wooden skull models were produced and used for experimental study. Comparisons of academic scores (mean and median) between active (students using the wooden skull) and control (students using natural skull) groups showed no statistically significant difference ( ≥ 0.05). Concerning the enhancement of learning skills, the wooden model was constructed in a way that would be able to enhance learning as it would be the natural skull. The wooden skull model, with more improvement in structural formation, can adequately facilitate the teaching and learning of anatomy of the human skull. This project and the experimental study about utilization of the wooden skull model provide a good potential of using the wooden models to supplement the use of the natural human skull.
Topics: Anatomy; Bignoniaceae; Curriculum; Education, Medical, Undergraduate; Educational Measurement; Humans; Learning; Models, Anatomic; Skull; Students, Medical; Teaching; Technology; Uganda; Wood
PubMed: 32908914
DOI: 10.1155/2020/8036737 -
Folia Morphologica 2022The foramen magnum (FM) is an important landmark because of its close relationship to key structures such as the brainstem and spinal cord, an extension of the medulla...
BACKGROUND
The foramen magnum (FM) is an important landmark because of its close relationship to key structures such as the brainstem and spinal cord, an extension of the medulla oblongata. Because of the similarity in their shape, the existence of a relationship between cranial length and anteroposterior diameter of the FM, and between cranial width and transverse diameter of the FM may reveal the magnificent harmony of the skull and FM. Based on this idea, we investigated the existence of this harmony in skulls that we used in our study.
MATERIALS AND METHODS
In this study, 60 adult dry skulls belonging to the Turkish population were examined. The anteroposterior and transverse diameters of the foramen magnum and the length and width of the skull were measured. Measurements were made directly on the skull using a digital sliding calliper. New indices and ratios were applied with those measurements.
RESULTS
Our study suggests that FM width and FM length could be estimated by using the cranial length and cranial width measurements in the skull by accepting the mean of these coefficients (4.62) as the golden ratio. The average of the coefficients of cranial width to FM width ratio (4.62 ± 0.35 [95% CI: 4.52-4.70]) and the average of the coefficients of cranial length to the FM length ratio (4.62 ± 0.50 [95% CI: 4.49-4.76]) were found to be equal to each other. In order to check the accuracy of this hypothesis, FM width and FM lengths were estimated with the help of new equations.
CONCLUSIONS
In the present study, the ratio between the anteroposterior and transverse diameters of both FM and the cranium was estimated at 4.62, indicating a magnificent harmony between cranial and subcranial structures. With this ratio, it is easy to estimate FM's size based on simple cranial measurements.
Topics: Foramen Magnum; Head; Pilot Projects; Skull; Spinal Cord
PubMed: 33634836
DOI: 10.5603/FM.a2021.0018