4,945 research outputs found
Corrected head position.
No full textBackground: Historically, many reference lines and planes of the human skull have been used in an attempt to depict the head in a natural head position (NHP) which is a relaxed/balanced position when looking ahead at their eye level. Head position correction has been attempted in fields such as anatomy, art, anthropology, orthodontics, oral and maxillofacial surgery, plastic surgery, and forensics. In orthodontics, oral and maxillofacial surgery, and plastic surgery, corrected head position (CHP) is particularly important for diagnosis of the normality/protrusion/retrusion of the patient’s facial skeleton. Usually a single plane, such as Frankfurt horizontal, is used to correct head position, but its angulation is variable between individuals, because each individual’s anatomy is unique. It has been found previously that the Neutral Horizontal Axis (NHA), Frankfurt horizontal (FH), Krogman-Walker plane (KW plane), and Palatal plane (P plane) demonstrated near parallelism, and these planes averaged -1 to -2 degrees from the true horizontal (HOR, which is a horizontal plane determined as being perpendicular to the earth’s gravitational force) with subjects in NHP. Methods: Craniofacial planes were measured in an Aboriginal Australian sample and in two contemporary samples obtained from Australian orthodontic practices, and the findings were compared with previous studies. Each sample consisted of 40 individuals (20 males and 20 females) with subjects in NHP. The Aboriginal Australian sample was longitudinal (T1, mean age 10 years; T2, mean age 14 years, and T3, mean age 18 years) enabling NHP to be assessed over approximately 8 years. A soft tissue Ear - nose plane (EN plane) was also investigated. Results: NHP reproducibility over 8 years demonstrated a mean of absolute difference of 2.9 degrees, with a range of differences from -7.9 to 8.2 degrees and a standard deviation of differences equal to 3.6 degrees. The Neutral Horizontal Axis (NHA), Frankfurt horizontal (FH), Krogman-Walker plane (KW plane), and Palatal plane (P plane) demonstrated near parallelism with each other, and averaged between 0 and -3 degrees from HOR. On average, EN plane was horizontal but was variable. Conclusions: NHP is not consistently reproducible at the individual level. For hard tissue images, the combined use of NHA, FH, KW plane, and P plane enables prediction of CHP. Additionally, the rectangular shape of the lower orbit - nasal airway region appears to be useful for correcting head position. In facial soft tissue images, EN plane in combination with other visual factors helps to correct head position. Simple geometry enables this head position correction to be performed from any view of the head where relevant landmarks are seen.Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 200
Chosen logistics processes in Škoda JS
No full textThis master thesis deals with the purchase and sale process in Škoda JS company. The aim of this work is to assess whether the setting of the purchase and sale process is met by the company also within a real business case, in compliance with set controls, and whether the degree of perfect delivery is sufficient. In the introduction, the author specifies the basic terms: logistics, logistic chain, customer benefits, information systems in logistics, buying and selling. The following chapter introduces Škoda JS company, including the sphere of its entrepreneurial activity. This chapter also deals with the nuclear power industry. In the crucial chapter, the author describes the process of purchase and sale in Škoda JS company and compares it with a real business case. In conclusion, the author evaluates discrepancies and suggests recommendations to avoid them
Return to driving after head injury
No full textObjectives:
To determine whether patients who return to driving after head injury can be considered safe to do so and to compare the patient characteristics of those who return to driving with those who do not.
Methods:
In a multicentre qualitative study ten rehabilitation units collectively registered 563 adults with traumatic brain injury during a 2.5 year period. Recruitment to the study varied from immediately after hospital admission to several years post injury. Patients and their families were interviewed around three to six months following recruitment. 383 (67.5%) subjects were interviewed within one year of injury, of whom 270 (47.6%) were interviewed within 6 months of injury. Main outcome measures were the presence or absence of driving related problems reported by drivers and ex-drivers, and scores on driving related items of the Functional Independence/Functional Assessment Measure (FIM+FAM).
Results:
Of the 563 patients 381 were drivers before the injury and 139 had returned to driving at interview. Many current drivers reported problems with behaviour (anger, aggression, irritability) (67 (48.2%)), memory ( 89 (64%)), concentration and attention (39 (28.1%)), and vision (39 (28.1%)). Drivers reported most driving-related problems as frequently as ex-drivers, main exceptions were epilepsy and community mobility. Current drivers scored significantly higher on the FIM+FAM (i.e. more independent), than ex-drivers. The driving group had sustained less severe head injuries than ex-drivers, nevertheless 78 (56.2%) of current drivers had received a severe head injury. Few (61, 16%) previous drivers reported receiving formal advice about driving following injury.
Conclusions:
The existence of problems which could significantly affect driving do not prevent patients returning to driving after TBI. Patients should be assessed for both mental and physical status before returning to driving after a head injury, and systems put in place to enable clear and consistent advice to be given to patients regarding driving
Kitware/vtk-js: v27.5.0
No full text27.5.0 (2023-05-11)
Features
WebXR: Add support for head-mounted augmented reality displays (1919ee4)
Performance Improvements
WebXR: Unify WebXR scene default physical factors (e1c7ca6
Scintigraphic assessment of bone status at one year following hip resurfacing : comparison of two surgical approaches using SPECT-CT scan
No full textObjectives: To study the vascularity and bone metabolism of the femoral head/neck following hip resurfacing arthroplasty, and to use these results to compare the posterior and the trochanteric-flip approaches.
Methods: In our previous work, we reported changes to intra-operative blood flow during hip resurfacing arthroplasty comparing two surgical approaches. In this study, we report the vascularity and the metabolic bone function in the proximal femur in these same patients at one year after the surgery. Vascularity and bone function was assessed using scintigraphic techniques. Of the 13 patients who agreed to take part, eight had their arthroplasty through a posterior approach and five through a trochanteric-flip approach.
Results: One year after surgery, we found no difference in the vascularity (vascular phase) and metabolic bone function (delayed phase) at the junction of the femoral head/neck between the two groups of patients. Higher radiopharmaceutical uptake was found in the region of the greater trochanter in the trochanteric-flip group, related to the healing osteotomy.
Conclusions: Our findings using scintigraphic techniques suggest that the greater intra-operative reduction in blood flow to the junction of the femoral head/neck, which is seen with the posterior approach compared with trochanteric flip, does not result in any difference in vascularity or metabolic bone function one year after surgery
Head and trunk movement strategies in quiet stance : from the deficit of vestibular loss to the expertise of tightrope walkers via prosthetic feedback
No full textIs the head more locked to the trunk or stabilised in space during quite stance? Does prosthetic vestibular feedback have a positive impact on movement strategies and muscle synergies of those with vestibular loss? Does training in tandem stance lead to improved movement strategies and/or reweighting of sensory inputs? These questions have not been answered to date. This thesis attempted to answer these questions with appropriate, but new, techniques. The coordination of the head with respect to the trunk and pelvis during quiet, feet side by side, stance in normal and vestibular loss subjects was examined as well as the effect of prosthetic feedback on the strategies and synergies used by vestibular loss subjects. Changes in movement strategies and sensory feedback in tight-rope walkers with considerable training in tandem stance (one foot before the other), were also investigated.
Subjects performed the stance tasks under different sensory conditions: with eyes open or closed, and on either a firm or foam surface. Stance was either side by side stance or tandem stance. For one experiment, vibrotactile and auditory balance feedback of trunk sway was used in addition. Subject groups were bilateral vestibular loss (BVL) patients, trained tightrope walkers and age matched controls. Two further groups of young and elderly healthy subjects were used to characterise differences in head movements with aging. In all studies roll and pitch angular velocities were recorded with six body-worn gyroscopes; a set of two worn at the upper trunk, an identical set at the hips and another lighter set worn on a head band. In one study with BVL subjects, another of the lighter gyroscopes was strapped onto the lower leg. For the balance feedback study surface EMGs were recorded from pairs of antagonistic muscles at the lower leg, trunk and upper arm. Data from all experiments was analysed in both time and frequency domains. For the analysis of tandem stance an estimate of centre of mass movement was calculated as well as its time to reach a virtual stability boundary.
The results indicated that under most sensory conditions, two legged, feet side by side stance conditions, head sway at the head for both the roll and pitch direction is greater than at the upper trunk and the pelvis. For low and mid-frequencies (<0.3 Hz) the head is locked to the trunk i.e. there is a tendency for the head and trunk to move as one unit but the head movement is always more than expected from a pure inverted pendulum movement mode. For the BVL subjects the head on trunk locking is more rigid and characterized by higher resonant frequencies. Prosthetic feedback reduced pelvis sway angle displacements in BVL subjects to values of age-matched healthy controls for all stance tasks. Movement strategies in BVL subjects were reduced in amplitudes with feedback but otherwise not changed. Reduced amplitudes are achieved with improved antagonistic muscle synergies. As we observed with feet side by side stance, tandem stance is also multisegmental. Keeping balance while standing on a tightrope appears to require similar intersegmental movement strategies for the head, trunk and pelvis to those used with other, less difficult tandem stance tasks. The difference with respect to untrained normal subjects is that faster trunk movements are used by tightrope walkers as they explore the limits of the base of support. At the same time they reduce relative head and pelvis movements to those of the trunk via changed proprioceptive weightings
Eccrine porocarcinoma of the head: An important differential diagnosis in the elderly patient
No full textBackground: Eccrine porocarcinoma is a rare malignant tumor of the sweat gland, characterized by a broad spectrum of clinicopathologic presentations. Surprisingly, unlike its benign counterpart eccrine poroma, eccrine porocarcinoma is seldom found in areas with a high density of eccrine sweat glands, like the palms or soles. Instead, eccrine porocarcinoma frequently occurs on the lower extremities, trunk and abdomen, but also on the head, resembling various other skin tumors, as illustrated in the patients described herein. Observations: We report 5 cases of eccrine porocarcinoma of the head. All patients were initially diagnosed as having epidermal or melanocytic skin tumors. Only after histopathologic examination were they classified as eccrine porocarcinoma, showing features of epithelial tumors with abortive ductal differentiation. Characteristic clinical, histopathologic and immunohistochemical findings of eccrine porocarcinomas are illustrated. Conclusion: Eccrine porocarcinomas are potentially fatal adnexal malignancies, in which extensive metastatic dissemination may occur. Porocarcinomas are commonly overlooked, or misinterpreted as squamous or basal cell carcinomas as well as other common malignant and even benign skin tumors. Knowledge of the clinical pattern and histologic findings, therefore, is crucial for an early therapeutic intervention, which can reduce the risk of tumor recurrence and serious complications. Copyright (c) 2008 S. Karger AG, Basel
Diffusion imaging shows abnormalities after blunt head trauma when conventional magnetic resonance imaging is normal
No full textThe investigation and management of patients after head injury must include the accurate and complete identification of cerebral damage. Using diffusion tensor imaging, abnormalities of diffusion in patients with head injuries and unremarkable MRI have been shown for the first time
Advanced head and neck cancer: Long-term results of chemo-radiotherapy, complications and induction of second malignancies
No full textBackground: Chemo-radiotherapy is superior to radiotherapy alone in the treatment of advanced, inoperable head and neck cancer. The long-term treatment results, the induction of second malignant tumors, and other long-term toxicities are not well defined. Patients and Methods: 100 consecutive patients with advanced head and neck cancer who were treated at our center were studied. Treatment results, survival, the occurrence of late complications, and second malignant tumors (SMT) were investigated. 78 patients were treated with a protocol combining cisplatinum, 5-fluorouracil, folinic acid and hyper-fractionated irradiation. 22 patients were treated with other chemo-radiotherapy protocols. The relative risk of developing an SMT was compared with that within the normal population. Results: The cumulative total probability of survival was 51.1% at 2 years and 38.7% at 4 years. The probability of relapse-free survival was 39.9% at 2 years and 36.7% at 4 years. A total of 7 patients developed SMT (4 cases of lung cancer, 2 colon cancers, 1 skin cancer). After 6 years, a cumulative risk of SMT of 8.7% was observed. The relative risk of developing an SMT was significantly increased (4.45-fold in males) compared with a normal population. 13 of 38 evaluable patients (34.2%) had severe late complications like fibrosis of soft tissues, nerve lesions, or were dependent on tracheal cannulas. Conclusions: The treatment results and long-term prognoses in our population of unselected high-risk patients are unsatisfactory, but comparable to those from multicenter studies. About 35% of patients become long-term (> 4 years) survivors. SMT generally occur early, have a poor prognosis and, most likely, are not treatment-related. Approximately 30% of long-term survivors have severe, often incapacitating late effects. The treatment and - if possible - prevention of these late effects is important for the quality of life of patients who survived advanced head and neck cancer
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