Search results for "BONE"
showing 10 items of 2629 documents
MRI radiomics-based machine-learning classification of bone chondrosarcoma.
2019
Abstract Purpose To evaluate the diagnostic performance of machine learning for discrimination between low-grade and high-grade cartilaginous bone tumors based on radiomic parameters extracted from unenhanced magnetic resonance imaging (MRI). Methods We retrospectively enrolled 58 patients with histologically-proven low-grade/atypical cartilaginous tumor of the appendicular skeleton (n = 26) or higher-grade chondrosarcoma (n = 32, including 16 appendicular and 16 axial lesions). They were randomly divided into training (n = 42) and test (n = 16) groups for model tuning and testing, respectively. All tumors were manually segmented on T1-weighted and T2-weighted images by drawing bidimensiona…
Implant treatment in atrophic posterior mandibles: Vertical regeneration with block bone grafts versus implants with 5.5-mm intrabony length
2014
Purpose: To retrospectively compare the outcomes of implants placed in posterior mandibles vertically regenerated with onlay autogenous block bone grafts and short dental implants. Materials and Methods: Consecutive patients with vertical bone atrophy in edentulous mandibular posterior regions (7 to 8 mm of bone above the inferior alveolar nerve) were treated with either implants placed in regenerated bone using autologous block bone grafts (group 1) or short implants (with 5.5-mm intrabony length) in native bone (group 2) between 2005 and 2010 and followed for 12 months after loading. The procedure used was the established treatment protocol for this type of patient at the Oral Surgery Uni…
Use of a new cross-linked collagen membrane for the treatment of dehiscence-type defects at titanium implants: a prospective, randomized-controlled d…
2009
OBJECTIVES The aim of the present randomized-controlled double-blinded clinical multicenter study was to assess the use of either a new cross-linked (VN) or a native collagen membrane (BG) for the treatment of dehiscence-type defects at titanium implants. MATERIAL AND METHODS A total of n=54 patients were recruited in four German university clinics. According to a parallel-groups design, dehiscence-type defects at titanium implants were filled with a natural bone mineral and randomly assigned to either VN or BG. Submerged sites were allowed to heal for 4 months. Primary (e.g., changes in defect length - DeltaDL, quality of newly formed tissue [0-4] - TQ) and secondary parameters (e.g., memb…
Clinical evaluation of nanocrystalline hydroxyapatite paste in the treatment of human periodontal bony defects--a randomized controlled clinical tria…
2008
The aim of this study was to compare the clinical outcome of intrabony periodontal defects following treatment with a novel nanocrystalline hydroxyapatite (NHA) paste to open flap debridement.Twenty-eight subjects, each displaying one intrabony defect with probing depth (PD)or =6 mm and radiographic evidence of an intraosseous componentor =3 mm participated in the present study. Subjects were allocated randomly to treatment with NHA paste (test group) or open flap debridement (control group). At baseline and at 6 months after surgery, the following clinical parameters were recorded by a masked examiner: plaque index, gingival index, PD, clinical attachment level (CAL), and gingival recessio…
Intraoperative C-arm CT imaging in angular stable plate osteosynthesis of distal radius fractures
2013
The purpose of this study was to analyze the practicability and benefit of intraoperative C-arm computed tomography (CT) imaging in volar plate osteosynthesis of unstable distal radius fractures. During a 1 year period, intraoperative three dimensional (3D) imaging with the ARCADIS Orbic 3D was performed in addition to standard fluoroscopy in 51 cases. The volar angular stable plate oesteosyntheses were analyzed intraoperatively and, if necessary, improved immediately. The duration of the scan and radiation exposure dose were measured. On average, performance of the scan and analysis of the CT dataset took 6.7 minutes. In 31.3% of the surgeries a misplacement of screws was detected and cor…
The influence of testosterone substitution on bone mineral density in patients with Klinefelter's syndrome.
2009
The aim of this study was to clarify the extent of bone mineral deficiency in patients with Klinefelter's syndrome on the premise that testosterone substitution could prevent this deficiency. Bone mineral density was measured by single-photon absorptiometry in 42 patients with Klinefelter's syndrome, (21 patients without therapy, 10 with testosterone substitution before the age of 20 and 11 patients with testosterone substitution beginning after the age of 20). We found significantly lower bone mineral density in patients without therapy and in patients when the therapy began later compared to normal individuals. Patients with early therapy showed a high proportion of normal values of bone …
The value of nuclear medicine for the diagnosis of spine diseases.
1993
Nuclear medicine examinations hold an important position in the diagnosis of diseases of the spine. During the last decade, decisive progress has been made in the field of instrumentation and radiopharmaceutical techniques: the use of high resolution collimators and the introduction of emission computer tomography as examples of improved instrumentation as well as 99m-Technetium red blood cell labelling as a new radiopharmaceutical technique. These present some of the developments responsible for the growing importance of scintigraphical diagnosis. Inflammatory processes of the vertebrae and the surrounding soft tissues can be detected or excluded with high reliability by the use of radionu…
Anatomic Changes After Hyoid Suspension for Obstructive Sleep Apnea: An MRI Study
2005
Objective To assess the effects of isolated hyoid suspension on subjective and objective parameters of obstructive sleep apnea and to evaluate changes in upper airway anatomy with the help of standardized magnetic resonance imaging. Study design and setting Fifteen patients received isolated hyoid suspension. Changes in respiratory disturbance index were assessed with polysomnography, and anatomical changes with standardized magnetic resonance imaging. Snoring, daytime sleepiness, and functional parameters were assessed with questionnaires. Lateral x-ray cephalometry was performed preoperatively. Results Mean respiratory disturbance index was reduced from 35.2 ± 19.1 to 27.4 ± 26.2. Forty p…
Surgical treatment and follow-up of solitary bone cyst of the mandible:a report of seven cases.
2001
We have operated on and followed up seven patients with simple mandibular bone cysts. The clinical data are shown in Table 1. All cysts were asymptomatic, and were found as a result of routine radiographs. They were all in dentulous areas in the mandible (5 in the anterior zone). Only case 5 gave a clear history of trauma in the region of the cyst 7 years before diagnosis. Vitality of the pulp of adjacent teeth was confirmed in all cases except case 6, in whom endodontic orthograde treatment of the teeth included in the lesion zone had previously been done. In all cases, the radiographs showed a unilocular radiotransparent lesion with clearly defined margins
Improved multilineage response of hematopoiesis in patients with myelodysplastic syndromes to a combination therapy with all-trans-retinoic acid, gra…
1996
Differentiation induction therapy is being tested in myelodysplastic syndromes to ameliorate maturation defects and to restore normal hematopoietic function. To this end, 17 patients (eight with refractory anemia, two with refractory anemia and ring sideroblasts, and seven with refractory anemia and excess of blast cells) were treated with a combination of all-trans-retinoic acid (ATRA), granulocyte colony-stimulating factor (G-CSF), erythropoietin (EPO), and alpha-tocopherol for durations of 8-16 weeks. Absolute neutrophil counts increased in all patients; platelet counts increased in five patients with discontinuation of transfusion needs in two of four transfusion-dependent patients. Sti…