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To better understand head injuries, human head finite element (FE) models have been reported in the literature. In scenarios where the head is directly impacted and measurements of head accelerations are not available, a high-quality skull model, as well as a high-quality brain model, is needed to predict the effect of impact on the brain through the skull. Furthermore, predicting cranial bone fractures requires comprehensively validated skull models. Lastly, high-quality meshes for both the skull and brain are needed for accurate strain/stress predictions across the entire head. Hence, we adopted a multi-block approach to develop hexahedral meshes for the brain, skull, and scalp simultaneously, a first approach in its kind. We then validated our model against experimental data of brain pressures (Nahum et al., 1977 ) and comprehensive skull responses (Yoganandan et al., 1995 , Yoganandan et al., 2004 , and Raymond et al., 2009 ). We concluded that a human head FE model was developed with capabilities to predict blunt- and ballistic-impact-induced skull fractures and pressure-related brain injuries.

Background This study aims at identifying orthodontic activities with the highest frequency of unfavorable/awkward and static postures held over a period of more than 4 s based on kinematic analysis. Moreover, a separate analysis of static postures for orthodontic and non-orthodontic activities serves to evaluate the duration for which these particular postures are assumed. Methods In total, 21 (13f/8 m) orthodontists (age: 31.5 ± 3.8 years) participated in this study. CUELA, a personal measurement system, was used to collect kinematic data for all orthodontic activities in a working day. Angle values of the head and torso were evaluated in accordance with ergonomic standards. Only those postures that were held statically for 4 s and longer were selected for further analysis. Alongside the kinematic analysis, the activities performed on-site were also subject to a detailed computerized analysis. The synchronization of data collected from both measurements arranges the patterns of posture found chronologically and in conjunction with the orthodontic activities performed ((I) “treatment” (II) “office” and (III) “other activities”). Results For (I) we observed an anterior inclination of the head and torso area as well as a twist of the head and neck area to the right. We found anterior back inclination and lateral back torsion to the right for (II) and (III). If, furthermore, we differentiate the duration of static postures, there are primarily short to medium-term (4–30s) static postures identified for (I). Also, categories (II) and (III) predominantly demonstrate static back postures with a duration of up to 30 s. With regard to (II) we observed that the back is ventrally inclined for 10.1% of the total activity duration. Conclusions During treatment static strains are observed in the entire head and torso area. On the contrary, static postures prevalent in the torso area are essential for activities of the other categories, particularly office work. These findings allow for a careful selection of unfavorable and static postures for each of the activities performed and help to develop specific preventive measures.

Background Manual paired‐point registration for navigated ENT‐surgery is prone to human errors; automatic surface registration is often caught in local minima. Methods Anatomical features of the human occiput are integrated into an algorithm for surface registration. A vector force field is defined between the patient and operating room datasets; registration is facilitated through gradient‐based vector field analysis optimization of an energy function. The method is validated exemplarily on patient surface data provided by a mechanically positioned A‐mode ultrasound sensor. Results Successful registrations were achieved within the entire parameter space, as well as from positions of local minima that were found by the Gaussian fields algorithm for surface registration. Sub‐millimetric registration error was measured in clinically relevant anatomical areas on the anterior skull and within the generally accepted margin of 1.5 mm for the entire head. Conclusion The satisfactory behavior of this approach potentially suggests a wider clinical integration.

A new species from the extinct ant genus Eocenomyrma, E. groehnisp. nov., is described based on worker from the Baltic amber (Late Eocene, Priabonian stage, 33.9–37.2 Ma). It the most resembles E. orthospina Dlussky et Radchenko, 2006 by shape of the propodeal spines and by the general appearance, but well differs from the latter by structure of the frontal carinae, which merging with the rugae that extend to the occipital margin; in contrary, the frontal carinae in E. orthospina are short, curve outwards and merge with the rugae, which surround antennal sockets. Additionally, entire head dorsum in E. groehni covered by the slightly sinuous longitudinal rugae, but in E. orthospina the only frons is with the not coarse longitudinal, slightly sinuous rugae, but the lateral parts of the head dorsum and occiput are with reticulation.

As children develop, they differ from adults in a number of important ways, including anatomy, metabolism, immune system, and the extent of myelination of the nervous system. As a consequence, equivalent exposures to radiation from mobile phones result in different doses to specific tissues in children compared with adults. Higher doses are likely to have more severe implications in the young. A young child’s skull is not only smaller and thinner than an adult’s, but also has dielectric characteristics closer to those of soft tissues, probably due to a higher water content. The young skull better matches the electromagnetic characteristics of the skin and brain. As a result, finite-difference time-domain (FDTD) simulations confirm field penetration and higher specific absorption rate (SAR) in deeper structures in the young brain. If the peak spatial SAR (psSAR) is modeled in the entire head, as current testing standards recommend, the results for adults and children are equivalent. Our anatomically based evaluations rely on FDTD simulations of different tissues within the brain and confirm that the psSAR in a child’s brain is higher than in an adult’s brain.

Mild traumatic brain injury (TBI) from focal head impact is the most common form of TBI in humans. Animal models, however, typically use direct impact to the exposed dura or skull, or blast to the entire head. We present a detailed characterization of a novel overpressure blast system to create focal closed-head mild TBI in mice. A high-pressure air pulse limited to a 7.5 mm diameter area on the left side of the head overlying the forebrain is delivered to anesthetized mice. The mouse eyes and ears are shielded, and its head and body are cushioned to minimize movement. This approach creates mild TBI by a pressure wave that acts on the brain, with minimal accompanying head acceleration-deceleration. A single 20-psi blast yields no functional deficits or brain injury, while a single 25-40 psi blast yields only slight motor deficits and brain damage. By contrast, a single 50-60 psi blast produces significant visual, motor, and neuropsychiatric impairments and axonal damage and microglial activation in major fiber tracts, but no contusive brain injury. This model thus reproduces the widespread axonal injury and functional impairments characteristic of closed-head mild TBI, without the complications of systemic or ocular blast effects or head acceleration that typically occur in other blast or impact models of closed-skull mild TBI. Accordingly, our model provides a simple way to examine the biomechanics, pathophysiology, and functional deficits that result from TBI and can serve as a reliable platform for testing therapies that reduce brain pathology and deficits.

For accurate simulation studies on distribution of electromagnetic field induced by Trancranial Magnetic Stimulation, a real human head conductivity model with deep cerebral structure was reconstructed from MRI raw data, by using of MIMICS and ANSYS. This model reflects geometric structural information of Scalp, Skull, Cerebrospinal Fluid (CSF), Gray Matter, White Matter, Cerebellum, Ventricle and Eye-balls. The ventricular structure has relatively higher conductivity, whose effect on induced field could not be neglected. This paper mainly introduces the method to establish the ventricle part of the entire head model, which is used for ANSYS low-frequency magnetic simulation, while the way to generate other parts is similar and accomplished. On the platform of-fered here, study on specific individual subject would be easy and practicable. Deep structures will be produced vectorial in the future work.

The aims of the present study were, first to develop a new method for evaluating sperm hyperactivation (HA) based on sperm head axis angle deviation, and second to apply this method in scoring selected sperm populations during capacitation. This was made possible by improving our original superimposed image analysis system (SIAS). The new option on the system enables us to determine the real angular deviation of the entire head in successive superimposed frames. The entire procedure for each spermatozoon requires 10-20 sec, according to the frame/rate utilized. A clear cut-off between the values of hyperactivated, transitional and non-hyperactivated spermatozoa was found at 11 and 21 frames/sec. However, at 6 frames/sec, a partial overlap between the three classes was found. We defined sperm activity as follows. At 11 frames/sec, hyperactivated: angle sumor = 405 degrees; transitional: 200 degreesor = angle sum405 degrees. At 21 frames/sec, hyperactivated: angle sumor = 760 degrees; transitional: 350 degreesor = angle sum760 degrees. The results, in agreement with previous research, show the peaks of activity at 3 h, dropping to a minimum at 6 h. This phenomenon was significantly more evident in fertile compared with subfertile semen samples.

A pituitary adenoma was diagnosed via histopathologic examination in an aged female Dumeril's ground boa, Acrantophis dumerili. The snake exhibited postural abnormalities, dull mentation, and poor muscle tone prior to death. Pituitary neoplasms appear to occur very rarely in reptiles, but may be underreported if the pituitary gland is not routinely examined. This report illustrates the importance of submitting the brain or entire head for microscopic evaluation.

✓ Although hair removal prior to neurosurgery may increase the risk of infection, the practice of shaving the patient's entire head is still common, particularly in implant surgery. The authors describe a technique for implanting a deep brain stimulation electrode without shaving the patient's hair and present a retrospective analysis of 261 implantations in 221 cases.

This paper presents Langwidere, a facial animation system that integrates hierarchical spline modeling with simulated muscles based upon local area surface deformations. The multi-level shape representation of a hierarchical spline provides control over the extent of deformations, while at the same time reducing the amount of data needed to define the surface. The facial model is constructed from a single closed surface defining the entire head and internal structures of the mouth cavity. Simulated muscles are attached to various levels of the surface with more rudimentary levels substituting for bone such as the skull and jaw. The combination of a hierarchical model and simulated muscles provides a smooth surface with precise and flexible control over surface shape. >

Purpose To determine whether the size and configuration of the optic chiasm in humans with albinism is different from that in normal control subjects. Methods Seventeen patients and 15 control subjects underwent magnetic resonance imaging of the entire head. Images were reformatted to the chiasm region and analyzed with observer-independent morphometry and measurements by a blinded observer. Results The albino group showed significantly smaller chiasmatic widths, smaller optic nerves and tracts, and wider angles between nerves and tracts. Statistical morphometry showed a different configuration of the optic chiasm. Conclusions Size and configuration of the optic chiasm in humans with albinism are distinctly different from those in normal control subjects and reflect the atypical crossing of optic fibers.

The plasmalemma of the mammalian spermatozoon contains a number of specific proteins, some of which have a clear regional distribution (see ref. 1–5). It is reasonable to assume that one or more sperm membrane proteins are involved in the initial recognition events of fertilization. We have isolated a number of boar sperm membrane glycoproteins and in this communication two of them will be described in some detail.

Summary Man's knowledge of human head proportions was investigated by asking young adult Ss to judge the relative location of selected head landmarks. Ss placed “x”s along a “vertical” line in a “unidimensional” condition, and within an oval outline of a head in two “bidimensional” conditions. Ss displaced landmarks upwards in both unidimensional and bidimensional conditions, with distortions by males exceeding those by females. On the bidimensional stimulus displays, landmarks were also displaced inwards toward the sagittal plane. The upward displacements of eyes and bottom of nose were the most noteworthy of the various distortions. Psychophysical experiments related to the present study suggest that the observed head landmark distortions are not likely attributable to anchoring effects. The findings also cast doubt on the hypothesis that Ss overestimate landmark heights because they treat the stimulus display as though it represents the face alone, rather than the entire head. Other explanations of the...

I. ASEPTIC PROTECTIVE SHEET FOR MASTOID SURGERY. One of the important problems confronting the aural surgeon is the maintenance of strict asepsis of the mastoid wound without unduly disfiguring the patient, even temporarily, by extensive removal of hair. The practice of different operators, as regards the preparation of the field for a mastoid operation, varies from removal of only a small amount of hair immediately surrounding the area to be opened, to a close shaving of the entire head. I have never felt justified in exposing an extensive area of the scalp, except in a premeditated brain investigation, and yet, in my efforts to save the patient from unnecessary loss of hair, I have frequently been sorely troubled by hairs encroaching on the wound at a critical stage of the operation. In preparing for a simple mastoidectomy it has been my custom to have the scalp shaved for a distance

It was found possible to demonstrate the presence of acid in nervous tissue by the use of phenolsulphonephthalein as an indicator. The latter was employed in a 0.2 per cent. solution in Ringer's fluid, made slightly alkaline by the addition of one part of M/15 Na2HPO4 to four parts Ringer. Pieces of nervous tissue immersed in this solution take up sufficient dye in thirty minutes to show a striking reaction. In order to observe the reaction in brain substance, the brain of a frog was exposed by the removal of the roof of the skull, and the entire head immersed in the solution of phenolsulphonephthalein. When the preparation was examined thirty minutes later, the injured parts of the brain were bright yellow, indicating an acidity at least equivalent to PH = 6.5. The uninjured parts remained pink, but subsequent injury to them brought about the yellow coloration in a few seconds.In similar fashion nerve trunks may be stained. The uninjured parts are pink, but crushed areas and the cut ends are yellow. Micr...

Stiffness of the neck is often found in clinical practice accompanying meningeal irritation. Yet, paradoxically enough, patients have been erroneously diagnosed as having had meningitis because of its presence. We had to note the conditions where stiff neck was found, for it soon became obvious that not all stiff necks were due to meningeal irritation. In order to establish a diagnosis when this condition is present, one has to collect the evidence based on inspection, percussion, palpation and rarely auscultation. The factors causing stiffness of the neck originate in nerves, muscles, bones, fascia, ligaments, glands and other structures. The neck is inspected from front, side and back. One notes how the head is held. Is it braced and splinted to avoid pain? Is there pain in certain positions only? Is pain absent? Is the entire head and neck moved in a marionette manner or is the neck stiffened so that

With our limited access to the literature we have been unable to find any satisfactory description for an arthroplasty of the shoulder-joint. Having a case for operation, we began the work on the cadaver and developed the following technic, which we believe is nearest anatomically correct of anything we have been able to find. In this operation we have utilized a portion of the short head of the biceps for a flap to interpose, because it is covered bymore dense tendinous sheath than any other structure in the neighborhood of the shoulder-joint, is correctly located anatomically and we believe in the majority of cases will furnish sufficient fascia and muscle to make a flap of necessary dimensions. The flap obtained is quite sufficient to line the glenoid fossa and cover the entire head of the humerus. In our clinical case there was considerable enlargement of the head of the humerus

Weanling rats whose bodies were lead-shielded, were X-irradiated to defined areas of the head. Body growth, incisal tooth development, and histopathology of the tongue and glossopharyngeal area (throat) were studied for a period of 7 weeks following irradiation. An X-ray dose of 2000 rads to the head and throat caused injury to the tongue and palate which resulted in a reduction in food intake and a marked loss in weight of the exposed rats. The more extensive the head area irradiated the higher the mortality, attaining 100 per cent deaths at 9-10 days when the entire head was irradiated. Irradiation of the throat only with 2000 rads elicited 50 per cent deaths. There was a persistent reduction in the growth rate of the survivors compared to that of non-irradiated controls. These effects were not seen if the base of the tongue only was irradiated. The maxillary incisors, which received 120 rads through the lead shielding, after 5-7 weeks were either lost or grew abnormally in all throat-irradiated rats. The same dose of X-radiation to the incisors of rats in which the base of the tongue only was irradiated, had no deleterious effect on their development. The possibility of a relationship between metabolic disturbances caused by throat irradiation, and growth of the incisors receiving low doses of X-radiation, is postulated and discussed. (Author)