Virtual reconstruction of the Canis arnensis type (Canidae, Mammalia) from the Upper Valdarno Basin (Italy, Early Pleistocene).

Taphonomic deformation, whether it be brittle or plastic, is possibly the most influential process hindering the correct understanding of fossil species morphology. This is especially true if the deformation affects type specimens or applies to or obscures taxonomically diagnostic or functionally significant traits. Target Deformation, a recently developed virtual manipulation protocol, was implemented to address this issue by applying landmark-guided restoration of the original, deformed fossils, using undeformed specimens (or parts thereof) of the same species as a reference. The enigmatic Early Pleistocene canid Canis arnensis provides a typical example of a fossil species in dire need of virtual restoration. Its lectotype specimen is heavily deformed and none of the few known skulls are well preserved, obscuring the recognition of its systematic and phylogenetic position. Our results indicate that the algorithm effectively countered the lectotype skull's laterolateral compression and its concomitant rostrocaudal elongation. Morphometrically, comparison of the retrodeformed cranium (IGF 867_W) with other specimens of the same species, and to other fossil and extant canid material, confirms IGF 867_W consistently clusters within C. arnensis variability. Overall, the evidence presented here confirms that Target Deformation provides a powerful tool to better characterize complex taxa like C. arnensis, whose knowledge is severely affected by the state of preservation of its fossil material.

Establishment of an Animal Model of Dog Bite Injuries.

Nowadays dog bite is becoming a world public health problem. Therefore, the study aimed to develop a dog bite animal model that is helpful to solve these problems. In this study, the skull of an adult dog was scanned. The three-dimensional model of the dog maxillofacial bones and dentition was built by MIMICS. Next, the model was printed with Co-Cr alloy by using selective laser sintering technology to develop the dog bite simulation pliers. Then, to simulate dog bite to most, the maximum bite force of the pliers was measured and actions contained in dog bite process was analyzed. Afterwards, according to action analysis results, rabbits were bitten by the prepared instrument in actions that simulate dog's bite. Finally, the reproducibility and controllability of this animal model of dog bite injuries was validated in an in vivo study. The results showed a reliable animal model of dog bite injuries has been developed in this study. The sites and severities of the injuries could be adjusted as the operator wishes and the animal model of dog bite injuries was highly repeatable. This study also indicates the feasibility of using digital technology in establishing animal bite models.

A hundred-year-old mystery-the reproductive mode and larval morphology of the enigmatic frog genus Allophryne (Amphibia; Anura; Allophrynidae).

Frogs of the Allophrynidae are an enigmatic family from South America. To date, published information is lacking regarding this group's reproductive biology and larval morphology. Here, we provide the first detailed description of the reproductive mode, developmental mode, and tadpole morphology for Allophryne ruthveni. We developed a captive breeding and rearing protocol for this species and then conducted a series of observations to describe aspects of its reproductive biology. In captivity, this species exhibits aquatic oviposition, where single eggs are laid ungrouped within a simple jelly capsule and are scattered free in the water column before sinking to develop on benthic substrates. We did not observe parental care nor any parental interactions with eggs post-fertilization. Tadpoles are characterized by an oval body, anteroventral oral disc, a labial tooth row formula of 2(2)/3, and a dextral vent tube. The buccopharyngeal cavity is marked by the presence of two pairs of infralabial papilla and four lingual papillae. Cranial morphology is characterized by the presence of the commissura quadratoorbital. This species possesses an additional slip of the m. rectus cervicis and of the m. levator arcuum branchialium III. We discuss our results in comparison with glassfrogs (Centrolenidae).

Cranial functional specialisation for strength precedes morphological evolution in Oviraptorosauria.

Oviraptorosaurians were a theropod dinosaur group that reached high diversity in the Late Cretaceous. Within oviraptorosaurians, the later diverging oviraptorids evolved distinctive crania which were extensively pneumatised, short and tall, and had a robust toothless beak, interpreted as providing a powerful bite for their herbivorous to omnivorous diet. The present study explores the ability of oviraptorid crania to resist large mechanical stresses compared with other theropods and where this adaptation originated within oviraptorosaurians. Digital 3D cranial models were constructed for the earliest diverging oviraptorosaurian, Incisivosaurus gauthieri, and three oviraptorids, Citipati osmolskae, Conchoraptor gracilis, and Khaan mckennai. Finite element analyses indicate oviraptorosaurian crania were stronger than those of other herbivorous theropods (Erlikosaurus and Ornithomimus) and were more comparable to the large, carnivorous Allosaurus. The cranial biomechanics of Incisivosaurus align with oviraptorids, indicating an early establishment of distinctive strengthened cranial biomechanics in Oviraptorosauria, even before the highly modified oviraptorid cranial morphology. Bite modelling, using estimated muscle forces, suggests oviraptorid crania may have functioned closer to structural safety limits. Low mechanical stresses around the beaks of oviraptorids suggest a convergently evolved, functionally distinct rhamphotheca, serving as a cropping/feeding tool rather than for stress reduction, when compared with other herbivorous theropods.

A proxy for brain-to-endocranial cavity index in non-neornithean dinosaurs and other extinct archosaurs.

Although the brain fills nearly the entire cranial cavity in birds, it can occupy a small portion of it in crocodilians. The lack of data regarding the volumetric correspondence between the brain and the cranial cavity hampers thorough assessments of the degree of encephalization in non-neornithean dinosaurs and other extinct archosaurs and, consequently, informed inferences regarding their cognitive capacities. Existing data suggest that, across extant archosaurs, the degree of endocranial doming and the volume of intracranial nonneural components are inversely related. We build upon this information to develop an equation relating these two anatomical features in non-neornithean dinosaurs and other extinct archosaurs. We rely on measurements of the endocast doming and brain-to-endocranial cavity (BEC) index in extant relatives of non-neornithean dinosaurs, namely, the crurotarsans Caiman crocodilus, Crocodylus niloticus, and Crocodylus porosus; the paleognaths Struthio camelus and Apteryx mantelli; and the fowl Macrocephalon maleo, Gallus gallus, Meleagris gallopavo, Phasianus colchicus, and Anas platyrhynchos. Applying the equation to representative endocasts from major clades of dinosaurs, we found that BEC varies from about 0.6 in ceratopsians and thyreophorans to around 0.7 in ornithopods, pachycephalosaurians, sauropods, and theropods. We, therefore, warn against the use of a catch-all value, like 0.5, and instead encourage refinement in the adoption of BEC across archosaurs.

Power-integrated, wireless neural recording systems on the cranium using a direct printing method for deep-brain analysis.

Conventional power-integrated wireless neural recording devices suffer from bulky, rigid batteries in head-mounted configurations, hindering the precise interpretation of the subject's natural behaviors. These power sources also pose risks of material leakage and overheating. We present the direct printing of a power-integrated wireless neural recording system that seamlessly conforms to the cranium. A quasi-solid-state Zn-ion microbattery was 3D-printed as a built-in power source geometrically synchronized to the shape of a mouse skull. Soft deep-brain neural probes, interconnections, and auxiliary electronics were also printed using liquid metals on the cranium with high resolutions. In vivo studies using mice demonstrated the reliability and biocompatibility of this wireless neural recording system, enabling the monitoring of neural activities across extensive brain regions without notable heat generation. This all-printed neural interface system revolutionizes brain research, providing bio-conformable, customizable configurations for improved data quality and naturalistic experimentation.

Apical expansion of calvarial osteoblasts and suture patency is dependent on fibronectin cues.

The skull roof, or calvaria, is comprised of interlocking plates of bones that encase the brain. Separating these bones are fibrous sutures that permit growth. Currently, we do not understand the instructions for directional growth of the calvaria, a process which is error-prone and can lead to skeletal deficiencies or premature suture fusion (craniosynostosis, CS). Here, we identify graded expression of fibronectin (FN1) in the mouse embryonic cranial mesenchyme (CM) that precedes the apical expansion of calvaria. Conditional deletion of Fn1 or Wasl leads to diminished frontal bone expansion by altering cell shape and focal actin enrichment, respectively, suggesting defective migration of calvarial progenitors. Interestingly, Fn1 mutants have premature fusion of coronal sutures. Consistently, syndromic forms of CS in humans exhibit dysregulated FN1 expression, and we also find FN1 expression altered in a mouse CS model of Apert syndrome. These data support a model of FN1 as a directional substrate for calvarial osteoblast migration that may be a common mechanism underlying many cranial disorders of disparate genetic etiologies.

Emigration of Greek Knowledge to the Arab World.

The period described in this chapter reflects activity prior to the establishment of surgical centers in Europe in the twelfth century. It is a kind of prologue to the reintroduction of high-quality surgical practice. Religious squabbles within Christianity led to European medicine and surgery, the principles of which were written in Greek, being transported eastwards into the region newly dominated by Islam. There the works were translated into Arabic and during three to four hundred years, the works were not only retained but were enriched by contributions from within Arab culture. This evolution naturally enough came to affect what happened next. However, one thing is clear and was even commented on as early as by Albucasis. The surgeon's respect and distinction within society had depreciated during the sojourn of medical science in the Islamic world, with physicians being regarded as distinctly superior beings. With regard to specific details related to opening the head there was broad consistency between the various authors all of whom seem to have been greatly influenced by Paul of Ægina. Thus, there is no mention of the crown trepan. Opening the skull was performed with the non-perforating trepans making small holes which were connected with chisels or lenticulars. The indication to do this was separation of the dura from the bone. Whether or not the sutures should be avoided when trepanning is not a topic mentioned in these writings. There was also no recommendation for prophylactic trepanation.

Late Middle Ages-Europe.

At the end of the late Middle Ages, there had been changes in indications for surgery, with prophylactic trepanation falling out of favor. The management of wounds and the methods for opening the cranium had become fairly standardized. Narrow non-plunging trepans were the preferred drills, and cranial openings were widened by the use of multiple drill holes connected with chisels of which the lenticular was preferred. Concerns about damaging the dura led Theodoric to delay trepanation until the clinical changes reflected separation of the dura from the cranium, at least in his view. Draining pus remained the main indication for trepanation. In no case was the level of consciousness considered in determining the need to open the cranium.

Trepanation technique.

The larger part of this chapter is concerned with the technique of drilling the cranium with a circular saw called a trepan or trephine. The terminology of the instrument is outlined. Safe use of the instrument includes probing the groove produced by its use and angling the drill so that it impinges on bone which hitherto has not been sawn through. There is then an account of how larger openings may be made by drilling multiple small holes and connecting them by means of a chisel.

Hippocrates (ca 460 BC to ca 370 BC).

The chapter begins with a review of some of the background thinking during Hippocrates time. The brain was considered to be the location of the soul which was the essence of subjective experience. However, this was not a brain function as such but rather a location where the pneuma reacted with the soul. Hippocrates' monograph on cranial trauma begins with a description of the bones and sutures. He then systematized the classification of cranial injury. He sensibly advised accurate diagnosis into one of the types of injury he described and supported extension of any skin opening to facilitate diagnosis of the bone, the injury of which was his primary concern. His description of operative technique has rarely been surpassed, placing emphasis on care and methods for the avoidance of further injury. He also emphasized the importance of probing during trepanation to avoid damaging the dura and underlying brain. In addition, he insisted on using water to cool the trepan. All of this was positive. However, the respect in which he was held in subsequent generations meant that two albeit understandable errors were perpetuated. The first error was the use of prophylactic trepanation to permit the drainage of the pus which he believed would inevitably develop under a fissure. The second was to avoid trepanning at sutures, the reasons for which proscription are not clearly stated. In conclusion, it may be noted that what limited reporting of results is available demonstrates that Hippocrates trepanations were largely not successful.

Rome-Galen (129 to ca. 216).

Over the last 50 years the significance of Galen's contributions to the arts of medicine and surgery have been increasingly recognized. Despite his errors, his contributions to medical and surgical practice have been profound. In the present context, his teachings on cranial surgical instruments and technique would continue to be influential throughout one and a half millenia. His technical advice was sound. His error about the anatomy of blood vessels supplying CNS were not of much consequence since the CNS would remain surgically inaccessible until the end of the 19th century. He reclassified fractures as extending to the diploe or through the internal table. Moreover, they could be simple, comminuted, depressed, or elevated. He did not mention indications or clinical changes, on the other hand he had many sensible remarks to make on the instrumentation required for cranial surgery. As will be seen in what follows, he was much quoted in justification of the decisions of his successors. The major errors of significance related to his description of the anatomy of the cranium and its sutures. His concern about the cranial attachment, vascular components and excretory functions of the sutures added to Hippocrates' concerns about their inherent weakness resulted in the teaching that trepanation should avoid these structures. This was to have a limiting effect on the placement of trepanation openings which was of no benefit to the patients. Moreover, his enthusiasm for bloodletting would also serve to potentiate Hippocrates teaching on this matter, to the advantage of nobody.

Prehistoric or current primitive cranial operations.

Humankind demonstrates boundless curiosity, mostly expressed through the activities of a small number of individuals, whose achievements affect all members of society. The extent and distribution of pre-historic trepanation and trepanation in contemporary unsophisticated societies are reviewed. In the great majority of cases the intention of trepanation has been therapeutic, even if the understanding of underlying pathophysiology is not the same as that which scientific societies now accept. This review demonstrates variation in surgical technique. In the Atlas Mountains it was unacceptable to operate on the cranial sutures whereas in New Ireland it was not important. Pain relief was unnecessary in Melanesia because the patients were largely unconscious following injury. In South America, there was access to the coca leaf which could help with pain relief. In East Africa, one patient described the application of a powder to his wound which was thought to be for pain relief. The nature of the powder remains unknown. There were differences in the indications for trepanation. In New Britain, the operation was performed only for cases of fracture. In nearby New Ireland, epilepsy and certain forms of mental disturbance were also indications. In North and East Africa, the indication was most frequently headache following trauma. Most of these trepanations did not involve drilling, which is the main subject of this book.

New insights into pterosaur cranial anatomy: X-ray imaging reveals palatal structure and evolutionary trends.

Among the least studied portion of the pterosaur skeleton is the palate, which tends to be poorly preserved and commonly only visible from one side (the ventral portion). Even in well-preserved specimens, the bones tend to be fused, with the limits of individual palatal elements obscured. To shed new light on this region, we employed advanced X-ray imaging techniques on the non-pterodactyloid Kunpengopterus (Wukongopteridae), and the pterodactyloids Dsungaripterus (Dsungaripteridae), Hongshanopterus (Istiodactylidae), and Hamipterus (Hamipteridae). Our analyses revealed the presence of sutures between palatal bones in Dsungaripterus and Kunpengopterus, which resulted in different interpretations of the relation between palatine, ectopterygoid, and pterygoid, leading to a new identification of the palatal openings. Furthermore, our study shows six main observations such as the variation of the angle between the palatine rami and the variation in the relative sizes of the palatal openings. We also point out that the presence of a maxillopalatine fenestra (previously identified as postpalatine fenestra), is unique within Diapsida. Although much more work needs to be done, we showed that advanced X-ray imaging techniques open a window for understanding pterosaur cranial anatomy and provide a new perspective for investigating the evolutionary history of these flying reptiles.

The non-decussating and decussating trigeminothalamic tracts in humans: A combination of connectome-based tractography and histological validation.

BACKGROUND: Functional anatomical research proposed the existence of a bilateral trigeminal ascending system although the anatomy trajectories of the trigeminothalamic connections cranial to the pons remain largely elusive. This study therefore aimed to clarify the anatomical distributions of the trigeminothalamic connections in humans. METHODS: Advanced deterministic tractography to an averaged template of diffusion tensor imaging data from 1065 subjects from the Human Connectome Project was used. Seedings masks were placed in Montreal Neurological Institute standard space by use of the BigBrain histological dataset. Waypoint masks of the sensory thalamus was obtained from the Brainnetome Atlas. RESULTS: Tractography results were validated by use of the BigBrain histological dataset and Polarized Light Imaging microscopy. The trigeminothalamic tract bifurcated into a decussating ventral and a non-decussating dorsal tract. The ventral and dorsal tracts ascended to the contralateral thalamus and ipsilateral thalamus and reflected the ventral trigeminothalamic tract and the dorsal trigeminothalamic tract, respectively. The projection of the ventral trigeminothalamic tract and the dorsal trigeminothalamic tract to both thalami confirm the existence of a bilateral trigeminothalamic system in humans. CONCLUSIONS: Because our study is strictly anatomical, no further conclusions can be drawn with regard to physiological functionality. Future research should explore if the dorsal trigeminothalamic tract and the ventral trigeminothalamic tract actually transmit signals from noxious stimuli, this offers potential in understanding and possibly treating neuropathology in the orofacial region.

In vivo validation of highly customized cranial Ti-6AL-4V ELI prostheses fabricated through incremental forming and superplastic forming: an ovine model study.

Cranial reconstructions are essential for restoring both function and aesthetics in patients with craniofacial deformities or traumatic injuries. Titanium prostheses have gained popularity due to their biocompatibility, strength, and corrosion resistance. The use of Superplastic Forming (SPF) and Single Point Incremental Forming (SPIF) techniques to create titanium prostheses, specifically designed for cranial reconstructions was investigated in an ovine model through microtomographic and histomorphometric analyses. The results obtained from the explanted specimens revealed significant variations in bone volume, trabecular thickness, spacing, and number across different regions of interest (VOIs or ROIs). Those regions next to the center of the cranial defect exhibited the most immature bone, characterized by higher porosity, decreased trabecular thickness, and wider trabecular spacing. Dynamic histomorphometry demonstrated differences in the mineralizing surface to bone surface ratio (MS/BS) and mineral apposition rate (MAR) depending on the timing of fluorochrome administration. A layer of connective tissue separated the prosthesis and the bone tissue. Overall, the study provided validation for the use of cranial prostheses made using SPF and SPIF techniques, offering insights into the processes of bone formation and remodeling in the implanted ovine model.

Injectable and In Situ Formed Dual-Network Hydrogel Reinforced by Mesoporous Silica Nanoparticles and Loaded with BMP-4 for the Closure and Repair of Skull Defects.

Bone defects are a common and challenging orthopedic problem with poor self-healing ability and long treatment cycles. The difficult-to-heal bone defects cause a significant burden of medical expenses on patients. Currently, biomaterials with mechanical stability, long-lasting action, and osteogenic activity are considered as a suitable way to effectively heal bone defects. Here, an injectable double network (DN) hydrogel prepared using physical and chemical cross-linking methods is designed. The first rigid network is constructed using methylpropenylated hyaluronic acid (HAMA), while the addition of chitosan oligosaccharide (COS) forms a second flexible network by physical cross-linking. The mesoporous silica nanoparticles (MSN) loaded with bone morphogenetic protein-4 (BMP-4) were embedded into DN hydrogel, which not only enhanced the mechanical stability of the hydrogel, but also slowly released BMP-4 to achieve long-term skull repair. The designed composite hydrogel showed an excellent compression property and deformation resistance. In vitro studies confirmed that the HAMA/COS/MSN@BMP-4 hydrogel had good biocompatibility and showed great potential in supporting proliferation and osteogenic differentiation of mouse embryo osteoblast precursor (MC3T3-E1) cells. Furthermore, in vivo studies confirmed that the DN hydrogel successfully filled and closed irregular skull defect wounds, effectively promoted bone regeneration, and significantly promoted bone repair compared with the control group. In addition, HAMA/COS/MSN@BMP-4 hydrogel precursor solution can quickly form hydrogel in situ at the wound by ultraviolet light, which can be applied to the closure and repair of wounds of different shapes, which provides the new way for the treatment of bone defects.

[Intraosseous cavernous hemangioma of the middle turbinate. Clinical cases]. / Vnutrikostnaya kavernoznaya gemangioma srednei nosovoi rakoviny. Klinicheskie sluchai.

Intraosseous vascular pathology of the turbinates is extremely rare in the practice of an otorhinolaryngologist and can be presented in various histopathological variants. The article presents two clinical cases in which an intraosseous cavernous hemangioma was hidden under the mask of a hypertrophied middle turbinate. The final diagnosis was established by the results of histological examination. The analysis of these clinical cases indicates that, despite the low prevalence, atypical clinical and CT picture, intraosseous formations of the nasal cavity can be of a vascular nature and certainly require a comprehensive examination, including CT, CT with contrast and/or MRI of the nose and paranasal sinuses. These clinical observations indicate that preliminary embolization of feeding vessels before surgical treatment is not required.

Resilient anatomy and local plasticity of naive and stress haematopoiesis.

The bone marrow adjusts blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses are unknown owing to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent haematopoiesis, erythropoiesis and lymphopoiesis in mice. We combine these with imaging of myelopoiesis1 to define the anatomy of normal and stress haematopoiesis. In the steady state, across the skeleton, single stem cells and multipotent progenitors distribute through the marrow enriched near megakaryocytes. Lineage-committed progenitors are recruited to blood vessels, where they contribute to lineage-specific microanatomical structures composed of progenitors and immature cells, which function as the production sites for each major blood lineage. This overall anatomy is resilient to insults, as it was maintained after haemorrhage, systemic bacterial infection and granulocyte colony-stimulating factor (G-CSF) treatment, and during ageing. Production sites enable haematopoietic plasticity as they differentially and selectively modulate their numbers and output in response to insults. We found that stress responses are variable across the skeleton: the tibia and the sternum respond in opposite ways to G-CSF, and the skull does not increase erythropoiesis after haemorrhage. Our studies enable in situ analyses of haematopoiesis, define the anatomy of normal and stress responses, identify discrete microanatomical production sites that confer plasticity to haematopoiesis, and uncover unprecedented heterogeneity of stress responses across the skeleton.

Customised pre-operative cranioplasty to achieve maximal surgical resection of tumours with osseous involvement-a case series.

PURPOSE: Surgical resection with bony margins would be the treatment of choice for tumours with osseous involvement such as meningiomas and metastasis. By developing and designing pre-operative customised 3D modelled implants, the patient can undergo resection of meningioma and repair of bone defect in the same operation. We present a generalisable method for designing pre-operative cranioplasty in patients to repair the bone defect after the resection of tumours. MATERIALS AND METHODS: We included six patients who presented with a tumour that was associated with overlying bone involvement. They underwent placement of customised cranioplasty in the same setting. A customised implant using a pre-operative imaging was designed with a 2-cm margin to allow for any intra-operative requirements for extending the craniectomy. RESULTS: Six patients were evaluated in this case series. Four patients had meningiomas, 1 patient had metastatic breast cancer on final histology, and 1 patient was found to have an intra-osseous arteriovenous malformation. Craniectomy based on margins provided by a cutting guide was fashioned. After tumour removal and haemostasis, the cranioplasty was then placed. All patients recovered well post-operatively with satisfactory cosmetic results. No wound infection was reported in our series. CONCLUSION: Our series demonstrate the feasibility of utilising pre-designed cranioplasty for meningiomas and other tumours with osseous involvement. Following strict infection protocols, minimal intra-operative handling/modification of the implant, and close follow-up has resulted in good cosmetic outcomes with no implant-related infections.