Search results for "Crew"
showing 10 items of 93 documents
Self-drilling and self-tapping miniscrews for osteosynthesis fixture after LeFort I osteotomy: An ex vivo trial for primary stability and a randomize…
2017
Abstract Background Self-drilling osteosynthesis screws (SDS) have a potential higher primary stability together with clinical advantages such as less time effort compared to self-tapping screws (STS). The aims of the study were to compare the primary stability of SDS and STS ex vivo and to analyze of the time-saving effect in vivo . Materials and methods Ex vivo , both screws were placed in porcine bone. Torque was measured for insertion and removal. Four specimens were kept in bone for histologic bone-to-implant-contact examination. In vivo , 49 patients who received orthognathic surgery in the maxilla were included in 2 centers. In a split-mouth design, the time for osteosynthesis fixati…
Straight and tilted implants for supporting screw-retained full-arch dental prostheses in atrophic maxillae : a 2-year prospective study
2018
Background To evaluate, over a 2-year period, the treatment outcomes for maxillary full-arch fixed dental prostheses (FDPs) supported by a combination of both tilted and axially-placed implants and to compare the marginal bone loss (MBL) and implant survival rates (SR) between tilted and axial implants. Material and Methods A retrospective study has been carried out. Thirty-two patients (16 males and 16 females) treated with maxillary full-arch FDPs were included in this retrospective study. A total of 187 implants were inserted to rehabilitate the fully edentulous maxillary arches: 36% of them were tilted (T group, n = 68) and the remaining 64% were axially placed (A group, n = 119). From …
Is Dexamethasone superior to Ketorolac in reducing pain, swelling and trismus following mandibular third molar removal? A split mouth triple-blind ra…
2021
Background The preemptive use of anti-inflammatory drugs, such as corticosteroids and NSAIDs, has the potential to reduce pain, swelling and trismus following oral surgery. The aim of this study was to compare the efficacy of dexamethasone and ketorolac tromethamine in reducing pain, swelling and trismus after mandibular third molar removal. Material and Methods The researches implemented a triple-blind, randomized clinical trial. The study was conducted with ASA I individuals aging between 18 and 35 years, which were randomized and submitted to two interventions, one with 8mg dexamethasone and the other with 20mg ketorolac tromethamine given 1h before the procedure. The primary predictor v…
Intraosseous Fixation Compared to Plantar Plate Fixation for First Metatarsocuneiform Arthrodesis
2014
Background: Metatarsocuneiform (MTC) fusion is a treatment option for management of hallux valgus. We compared the biomechanical characteristics of an internal fixation device with plantar plate fixation. Methods: Seven matched pairs of feet from human cadavers were used to compare the intramedullary (IM) device plus compression screw to plantar plate combined with a compression screw. Specimen constructs were loaded in a cyclic 4-point bending test. We obtained initial/final stiffness, maximum load, and number of cycles to failure. Bone mineral density was measured with peripheral quantitative computed tomography. Performance was compared using time to event analysis with number of cycles …
Epidemiological investigations of aircrew: an occupational group with low-level cosmic radiation exposure.
2012
Aircrew and passengers are exposed to low-level cosmic ionising radiation. Annual effective doses for flight crew have been estimated to be in the order of 2-5 mSv and can attain 75 mSv at career end. Epidemiological studies in this occupational group have been conducted over the last 15-20 years, usually with a focus on radiation-associated cancer. These studies are summarised in this note. Overall cancer risk was not elevated in most studies and subpopulations analysed, while malignant melanoma, other skin cancers and breast cancer in female aircrew have shown elevated incidence, with lesser risk elevations in terms of mortality. In some studies, including the large German cohort, brain c…
Radiolucent Carbon Fiber–Reinforced Pedicle Screws for Treatment of Spinal Tumors: Advantages for Radiation Planning and Follow-Up Imaging
2016
Objective Surgical treatment of spinal tumors regularly includes spinal instrumentation with pedicle screws. Most modern pedicle screws are made of titanium alloy, which is associated with artifacts on postoperative imaging such as computed tomography and/or magnetic resonance imaging. These artifacts hamper radiation treatment planning and execution and follow-up imaging. Recently, carbon fiber–reinforced polyetheretherketone (CFRP) implants became available for posterior instrumentation with the aim to reduce imaging artifacts by implants. Methods Patients harboring spinal tumors underwent posterior stabilization using CFRP pedicle screws. Postoperative imaging was evaluated for implant a…
Local and systemic risk factors influencing the long-term success of angular stable alloplastic reconstruction plates of the mandible
2013
Introduction: After ablative surgery of the mandible, angular stable alloplastic reconstruction plates are commonly employed. The aim of the study was a long-term evaluation of local anatomical, as looking at systemic factors influencing specific complications and the failure rate of such plates. Materials and methods: In a retrospective study covering an 11-year period, we reviewed the outcomes of angular stable plates of patients who had a segmental resection of the mandible and subsequent alloplastic reconstruction. Complications and failure rates were assessed and local (anatomical size and localization of resection) as well as systemic risk factors (age, sex, radiation therapy, smoking…
Number and Locations of Screw Fixation for Volar Fixed-Angle Plating of Distal Radius Fractures: Biomechanical Study
2010
Purpose To compare the biomechanical properties of different numbers and locations of screws in a multidirectional volar fixed-angle plate in a distal radius osteotomy cadaver model. Methods We created an extra-articular fracture in 16 pairs of fresh-frozen human cadaver radiuses. The 32 specimens were randomized into 4 groups. All fractures were fixated with a multidirectional volar fixed-angle plate. We tested 4 different screw-placement options in the distal fragment. The distal fragment was fixed with 4 locking screws in the distal row of the plate in group a, and with 4 locking screws alternately in the distal and proximal rows in group b. In group c, 3 locking screws were used in the …
Is there a role for percutaneous pelvic and acetabular reconstruction?
2007
The primary goal in the treatment of pelvic fractures is the restoration of haemodynamic stability. The secondary goal is the reconstruction of stability and symmetry of the pelvic ring. Percutaneous reconstruction can only be accepted if these goals are met. The type of definitive surgery is dependent of the degree of instability of the anterior and posterior pelvic ring. Retrograde transpubic screw fixation of pubic rami fractures is a good alternative to external fixation or plate and screw osteosynthesis. The technique of screw placement and image intensifier control is explained. Internal fixation of pure sacroiliac dislocations, fracture-dislocations of the sacroiliac joint and sacral…
Dislocation interaction with C in α-Fe: a comparison between atomic simulations and elasticity theory
2008
International audience; The interaction of C atoms with a screw and an edge dislocation is modelled at an atomic scale using an empirical Fe-C interatomic potential based on the Embedded Atom Method (EAM) and molecular statics simulations. Results of atomic simulations are compared with predictions of elasticity theory. It is shown that a quantitative agreement can be obtained between both modelling techniques as long as anisotropic elastic calculations are performed and both the dilatation and the tetragonal distortion induced by the C interstitial are considered. Using isotropic elasticity allows to predict the main trends of the interaction and considering only the interstitial dilatatio…