This case is a 19-year-old soldier who suffered a combined elbow dislocation and posterior Monteggia fracture and dislocation (type II). The ulna fracture was managed by ORIF. The elbow dislocation was managed by closed reduction and immobilization in 900 flexion. The posteriorly dislocated radial head was kept reduced by a transarticular pin. After 6 months elbow and forearm motion was restric...

This thesis consists of two parts. The first part explores a 2-d edge dislocation model to demonstrate characteristics of Field Dislocation Mechanics (FDM) in modeling single and collective behavior of individual dislocations. The second work explores the possibility of modelling adiabatic shear bands propagation within the timespace averaged framework of Mesoscopic Field Dislocation Mechanics ...

Mechanical obstacles may infrequently impede closed reduction of anterior shoulder dislocation. Imaging techniques such as arthrography, computed tomography (CT) and magnetic resonance imaging (MRI) complement conventional radiography by allowing identification of obstacles to reduction. We present a case of irreducible anterior glenohumeral dislocation resulting from an initial anterior disloc...

background bleaching of traumatized discolored teeth is considered an important issue in esthetic dentistry. various methods have been introduced for bleaching, some of which may have adverse effects on soft or hard tissues of the tooth. objectives the objective of the study was to evaluate the effects of ktp laser bleaching on enamel of traumatized teeth. materials and methods a square of 36 m...

A series of massively parallel molecular dynamics simulations with up to 35 million atoms is performed to investigate dislocation emission from a three-dimensional crack. We observe dislocation loops emitted from the crack front|the rst time this has been seen in computer simulations. The sequence of dislocation emission in the process of crack blunting process strongly depends on the crystallo...

In this Letter, we propose a model that demonstrates the effect of a free surface on the lattice resistance experienced by a moving dislocation in nanodimensional systems. This effect manifests in an enhanced velocity of dislocation due to the proximity of the dislocation line to the surface. To verify this finding, molecular dynamics simulations for an edge dislocation in bcc molybdenum are pe...

Plastic deformation mediated by collective dislocation dynamics is investigated in the two-dimensional phase-field crystal model of sheared single crystals. We find that intermittent fluctuations in the dislocation population number accompany bursts in the plastic strain-rate fluctuations. Dislocation number fluctuations exhibit a power-law spectral density 1/f2 at high frequencies f. The proba...

Numerical studies of dislocation pair correlations have played a central role in deriving a continuum theory from the equations of motion of 2D dislocation systems in a mathematically rigorous way. As part of an effort to extend this theory into the full 3D dislocation problem, 3D dislocation pair correlations were studied with discrete dislocation dynamics simulation. As a first approximation,...

The mechanisms of dislocation intersection and strain hardening in fcc crystals are examined with emphasis on the process of junction formation and destruction. Large-scale 3D simulations of dislocation dynamics were performed yielding access for the first time to statistically averaged quantities. These simulations provide a parameter-free estimate of the dislocation microstructure strength an...

Posterior dislocation of the shoulder is a rare injury that occurs secondary to trauma and seizures. Diagnosis is often missed and treatment is challenging. Neglected posterior dislocation is associated with Hill-Sachs lesion which leads to locking of dislocation. Correct diagnosis is achieved by history taking, a physical examination and appropriate imaging. In neglected shoulder dislocation w...