The Rouyn-Noranda area in the center of the Abitibi subprovince is composed of comparatively unmetamorphosed Archean volcanics of Blake River Group (ERG). Rouyn-Nornada is one of the lozenge shaped structural blocks in the area bounded by the Porcupine Destor Fault (PDF) zone and the Larder Lake Caddilac Fault (LCF) zone. 160 samples were collected from 29 different sites selected to lie in the center of the block, at or near the PDF zone and accross the PDF zone in the neighboring lozenge. Stable magnetizations have been obtained from the central relatively unstrained parts of the lozenges. These magnetizations show some improvement in precision statistics after structural corrections implying that they are pre-folding and probably Archean in age. Sites along the PDF zone show scattered magnetizations, which do not agree at sample or site level. The Zone I (Sites in the center of the Rouyn-Noranda block) structurally corrected mean direction (D=154.0, I=-95.0, k=19.0, a95 =19.0, N=6 sites) differ from the Zone III (Sites from the center of the adjacent block) mean direction (D=214.0, I=-49.0, k=16.0, a95 =92.0) by 60+/-37° implying that the Rouyn-Norand block have rotated anti-clockwise by 60+/-37° about a vertical axis relative to the adjacent structural block. / Thesis / Master of Science (MS)

Introduction: The purpose of the study was to evaluate the effects of maxillomandibular advancement (MMA) surgery with counterclockwise rotation on soft tissue oral and nasal structures. Materials and Methods: This retrospective study included 34 subjects diagnosed with OSA who underwent MMA at the Stanford Sleep Clinic. Initial (T1) and Final (T2) CBCTs were evaluated and compared for 10 hard tissue and 15 soft tissue measurements. Additionally, the external nasal valve surface area was measured and compared between the two time points. A 3D superimposition was performed and used to evaluate the relative hard and soft tissue movements. Results: There was a linear correlation in the advancement of the maxilla to the sagittal movement of the upper lip of 75%, while the mandibular soft tissue moved 91-93% of the mandibular sagittal position. The interalar width and mouth width increased significantly following surgery while the lower vermillion border length decreased significantly. There was a clinically significant increase in the average surface area of the external nasal valve by 28%. No correlations were found between maxillary impaction and soft tissue oral or nasal measurements. Conclusion: MMA with CCW results in significant changes to the soft tissue nose and oral region. Soft tissue planning must be considered to maintain desirable esthetics following surgery.

The Kinsevere mine is a copper deposit located in the Democratic Republic of Congo (DRC), within the Central African Copperbelt. This area is situated in the Katangan basin within the SE portion of the Lufilian Arc, which is a large, arcuate structure that extends from SE Angola, across the DRC, and into NW Zambia. The purpose of this study is to characterise the brittle deformation observed around the Kinsevere copper deposit to lead to an understanding of the deformation history of the area. This is accomplished by analysing fault-slip and fold data to help understand the relationship between regional palaeostress, faulting and folding present in the mine vicinity. This study also attempts to characterise fracture-controlled copper mineralisation within the interpreted geodynamic context of the area. The broader objective of this study is to relate the structural observations from Kinsevere to the deformation history of the Lufilian Arc. This study uses the right dihedral method to analyse four categories of brittle structures. The structural types analysed include slickensided faults, mineralised joints, and unmineralised joints and shear fractures. The data suggests that the palaeostress associated with the formation of brittle structures in the Kinsevere area occurred during three deformation events. The first event is characterised by a compressional stress regime which occurred during the early stage of the Kolwezian phase (D1). The second event is characterised by a strike-slip stress regime that formed as the result of clockwise rotation of the earlier (D1) compressional regime. Two fault-slip vectors were observed on the strike-slip fault planes, indicating that a reactivation occurred during the Monwezian phase (D2). The final structural event was characterised by the development of an extensional stress regime. This was associated with North-South oriented extension and is related to the East African Rift System (D3). These interpreted events correlate well with the geodynamic context related to the Lufilian orogeny. Another line of evidence that supports this structural interpretation is the presence of evaporitic minerals observed in the stratigraphic units surrounding the brecciated zones such as the RAT and the CMN. The structural association of these evaporitic minerals may be related to pre-existing, salt-bearing units, which were dissolved during an early compressive (D1) phase of the Lufilian orogeny. However, the contact between the Grey RAT and the Red RAT (distal from the breccia zones) does not show any evidence of faulting, and in the Kinsevere area the Grey RAT is always observed above the Red RAT. This suggests that the Grey RAT may be the uppermost stratigraphic unit of the RAT subgroup, which contradicts some previously published interpretations. Thus, the current structural architecture was probably formed from a combination of two separate mechanisms, including compression-related salt extrusion and the development of thrust faults and folding resulting from the shortening of the Katangan basin. Based on an analysis of the fracture-controlled mineralisation in the study area, it is shown here that most of the stress tensors indicate that these fractures were induced within the compressional stress regime generated by the Lufilian orogeny. This conclusion supports studies which suggest a multiphase origin for the mineralizing fluids active in the Katangan basin. Thus, the age of the copper mineralisation associated with fractures is interpreted to correlate with the timing of the folding event that occurred during the Lufilian orogeny between 540-550Ma. / Dissertation (MSc)--University of Pretoria, 2012. / Geology / unrestricted

Orthognatic surgery deals with congenital and acquired dentoalveolar or skeletal deformities of the face. An unfavourable downward rotation of a mandible and posterior vertical maxillary excess cause an anterior open bite, which is characterized by excessive anterior facial height in the lower third, a gap between the incisors in maximal occlusion and a large mandibular angle. Osteotomy (mainly Le Fort I osteotomy or bilateral sagittal split osteotomy of the mandibular ramus - BSSO), ostectomy or distraction osteogenesis are performed to correct the orthognatic deformities. Osteosynthetic materials based on titanium or bioresorbable materials are used in the form of miniplates with monocortical screws, or bicortical screws are utilized to fix the bony fragments. Stability of the new jaws position is the main criterion for success. Relapse causes a loss of occlusion and consequently functional and aesthetic disorders. Relapse consists of skeletal and dental factors. Skeletal relapse is usually divided into early and long-term relapse. BSSO with counter-clockwise (CCW) rotation of the occlusal plane alone was traditionally considered to be the least stable treatment method. Some authors suggest the use of two miniplates on each side of the osteotomy, but we have not found scientific proof of the...

Orthognatic surgery deals with congenital and acquired dentoalveolar or skeletal deformities of the face. An unfavourable downward rotation of a mandible and posterior vertical maxillary excess cause an anterior open bite, which is characterized by excessive anterior facial height in the lower third, a gap between the incisors in maximal occlusion and a large mandibular angle. Osteotomy (mainly Le Fort I osteotomy or bilateral sagittal split osteotomy of the mandibular ramus - BSSO), ostectomy or distraction osteogenesis are performed to correct the orthognatic deformities. Osteosynthetic materials based on titanium or bioresorbable materials are used in the form of miniplates with monocortical screws, or bicortical screws are utilized to fix the bony fragments. Stability of the new jaws position is the main criterion for success. Relapse causes a loss of occlusion and consequently functional and aesthetic disorders. Relapse consists of skeletal and dental factors. Skeletal relapse is usually divided into early and long-term relapse. BSSO with counter-clockwise (CCW) rotation of the occlusal plane alone was traditionally considered to be the least stable treatment method. Some authors suggest the use of two miniplates on each side of the osteotomy, but we have not found scientific proof of the...