Displaying publications 101 - 120 of 169 in total

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  1. Pan KL, Ong GB, Potukuchi AP
    Med J Malaysia, 2006 Dec;61 Suppl B:55-7.
    PMID: 17600994
    We report a case of an 11-year-old boy with osteosarcoma of the proximal humerus treated with wide excision and reconstruction with a cement spacer-prosthesis. After seven years of follow-up, the patient is now almost a young adult. We present his current physical and functional status, which seems to defray the initial doubts regarding long-term problems when we chose this method of reconstruction.
    Matched MeSH terms: Prosthesis Design
  2. Patil PG, Nimbalkar-Patil SP, Karandikar AB
    J Contemp Dent Pract, 2014 Jan 1;15(1):112-5.
    PMID: 24939276
    This case report demonstrates sequential periodontic, orthodontic and prosthodontic treatment modalities to save and restore deep horizontally fractured maxillary central incisor. The location of fracture was deep in the mucosa which reveals less than 2 mm of tooth structure to receive the crown. The procedures like surgical crown lengthening, endodontic post placement, orthodontic forced eruption, core build-up and metal-ceramic crown restoration were sequentially performed to conserve the fractured tooth. Forced eruption is preferred to surgical removal of supporting alveolar bone, since forced eruption preserves the biologic width, maintains esthetics, and at the same time exposes sound tooth structure for the placement of restorative margins.
    Matched MeSH terms: Dental Prosthesis Design
  3. B Jamayet N, J Abdullah Y, A Rajion Z, Husein A, K Alam M
    Bull. Tokyo Dent. Coll., 2017;58(2):117-124.
    PMID: 28724860 DOI: 10.2209/tdcpublication.2016-0021
    The wax sculpting of a maxillofacial prosthesis is challenging, time-consuming, and requires great skill. Rapid prototyping (RP) systems allow these hurdles to be overcome by enabling the creation of a customized 3D model of the desired prosthesis. Geomagic and Mimics are the most suitable software programs with which to design such prostheses. However, due to the high cost of these applications and the special training required to operate them, they are not widely used. Additionally, ill-fitting margins and other discrepancies in the final finished products of RP systems are also inevitable. Therefore, this process makes further treatment planning difficult for the maxillofacial prosthodontist. Here, we report the case of a 62-year-old woman who attended our clinic. Initially, she had presented with a right facial defect. This was later diagnosed as a squamous cell carcinoma and resected. The aim of this report is to describe a new technique for the 3D printing of facial prostheses which involves the combined use of open-source software, an RP system, and conventional methods of fabrication. The 3D design obtained was used to fabricate a maxillofacial prosthesis to restore the defect. The patient was happy with the esthetic outcome. This approach is relatively easy and cheap, does not require a high degree of non-medical training, and is beneficial in terms of clinical outcome.
    Matched MeSH terms: Prosthesis Design/methods
  4. Harwant S
    Med J Malaysia, 2004 Dec;59 Suppl F:2.
    PMID: 15941152
    Matched MeSH terms: Prosthesis Design
  5. Wahab AH, Kadir MR, Harun MN, Kamarul T, Syahrom A
    Med Biol Eng Comput, 2017 Mar;55(3):439-447.
    PMID: 27255451 DOI: 10.1007/s11517-016-1525-6
    The present study was conducted to compare the stability of four commercially available implants by investigating the focal stress distributions and relative micromotion using finite element analysis. Variations in the numbers of pegs between the implant designs were tested. A load of 750 N was applied at three different glenoid positions (SA: superior-anterior; SP: superior-posterior; C: central) to mimic off-center and central loadings during activities of daily living. Focal stress distributions and relative micromotion were measured using Marc Mentat software. The results demonstrated that by increasing the number of pegs from two to five, the total focal stress volumes exceeding 5 MPa, reflecting the stress critical volume (SCV) as the threshold for occurrence of cement microfractures, decreased from 8.41 to 5.21 % in the SA position and from 9.59 to 6.69 % in the SP position. However, in the C position, this change in peg number increased the SCV from 1.37 to 5.86 %. Meanwhile, micromotion appeared to remain within 19-25 µm irrespective of the number of pegs used. In conclusion, four-peg glenoid implants provide the best configuration because they had lower SCV values compared with lesser-peg implants, preserved more bone stock, and reduced PMMA cement usage compared with five-peg implants.
    Matched MeSH terms: Prosthesis Design*
  6. Abbas SS, Nasif MS, Al-Waked R, Meor Said MA
    Artif Organs, 2020 Feb;44(2):E20-E39.
    PMID: 31378963 DOI: 10.1111/aor.13536
    Platelet activation induced by shear stresses and non-physiological flow field generated by bileaflet mechanical heart valves (BMHVs) leads to thromboembolism, which can cause fatal consequences. One of the causes of platelet activation could be intermittent regurgitation, which arises due to asynchronous movement and rebound of BMHV leaflets during the valve closing phase. In this numerical study, the effect of intermittent regurgitation on the platelet activation potential of BMHVs was quantified by modeling a BMHV in the straight and anatomic aorta at implantation tilt angles 0°, 5°, 10°, and 20°. A fully implicit Arbitrary Lagrangian-Eulerian-based Fluid-Structure Interaction formulation was adopted with blood modeled as a multiphase, non-Newtonian fluid. Results showed that the intermittent regurgitation and consequently the platelet activation level increases with the increasing implantation tilt of BMHV. For the straight aorta, the leaflet of the 20° tilted BMHV underwent a rebound of approximately 20° after initially closing, whereas the leaflet of the 10°, 5°, and 0° tilted BMHVs underwent a rebound of 8.5°, 3°, and 0°, respectively. For the anatomic aorta, the leaflet of the 20° tilted BMHV underwent a rebound of approximately 24° after initially closing, whereas the leaflet of the 10°, 5°, and 0° tilted BMHVs underwent a rebound of 14°, 10°, and 7°, respectively. For all the implantation orientations of BMHVs, intermittent regurgitation and platelet activation were always higher in the anatomic aorta than in the straight aorta. The study concludes that the pivot axis of BMHV must be implanted parallel to the aortic root's curvature to minimize intermittent regurgitation and platelet activation.
    Matched MeSH terms: Prosthesis Design
  7. Al-Fakih E, Arifin N, Pirouzi G, Mahamd Adikan FR, Shasmin HN, Abu Osman NA
    J Biomed Opt, 2017 Aug;22(8):1-8.
    PMID: 28822140 DOI: 10.1117/1.JBO.22.8.087001
    This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction.
    Matched MeSH terms: Prosthesis Design
  8. Farook TH, Barman A, Abdullah JY, Jamayet NB
    J Prosthodont, 2021 Jun;30(5):420-429.
    PMID: 33200429 DOI: 10.1111/jopr.13286
    PURPOSE: Mesh optimization reduces the texture quality of 3D models in order to reduce storage file size and computational load on a personal computer. This study aims to explore mesh optimization using open source (free) software in the context of prosthodontic application.

    MATERIALS AND METHODS: An auricular prosthesis, a complete denture, and anterior and posterior crowns were constructed using conventional methods and laser scanned to create computerized 3D meshes. The meshes were optimized independently by four computer-aided design software (Meshmixer, Meshlab, Blender, and SculptGL) to 100%, 90%, 75%, 50%, and 25% levels of original file size. Upon optimization, the following parameters were virtually evaluated and compared; mesh vertices, file size, mesh surface area (SA), mesh volume (V), interpoint discrepancies (geometric similarity based on virtual point overlapping), and spatial similarity (volumetric similarity based on shape overlapping). The influence of software and optimization on surface area and volume of each prosthesis was evaluated independently using multiple linear regression.

    RESULTS: There were clear observable differences in vertices, file size, surface area, and volume. The choice of software significantly influenced the overall virtual parameters of auricular prosthesis [SA: F(4,15) = 12.93, R2 = 0.67, p < 0.001. V: F(4,15) = 9.33, R2 = 0.64, p < 0.001] and complete denture [SA: F(4,15) = 10.81, R2 = 0.67, p < 0.001. V: F(4,15) = 3.50, R2 = 0.34, p = 0.030] across optimization levels. Interpoint discrepancies were however limited to <0.1mm and volumetric similarity was >97%.

    CONCLUSION: Open-source mesh optimization of smaller dental prostheses in this study produced minimal loss of geometric and volumetric details. SculptGL models were most influenced by the amount of optimization performed.

    Matched MeSH terms: Dental Prosthesis Design
  9. Sadollah A, Bahreininejad A
    J Mech Behav Biomed Mater, 2011 Oct;4(7):1384-95.
    PMID: 21783149 DOI: 10.1016/j.jmbbm.2011.05.009
    Despite dental implantation being a great success, one of the key issues facing it is a mismatch of mechanical properties between engineered and native biomaterials, which makes osseointegration and bone remodeling problematical. Functionally graded material (FGM) has been proposed as a potential upgrade to some conventional implant materials such as titanium for selection in prosthetic dentistry. The idea of an FGM dental implant is that the property would vary in a certain pattern to match the biomechanical characteristics required at different regions in the hosting bone. However, matching the properties does not necessarily guarantee the best osseointegration and bone remodeling. Little existing research has been reported on developing an optimal design of an FGM dental implant for promoting long-term success. Based upon remodeling results, metaheuristic algorithms such as the genetic algorithms (GAs) and simulated annealing (SA) have been adopted to develop a multi-objective optimal design for FGM implantation design. The results are compared with those in literature.
    Matched MeSH terms: Dental Prosthesis Design/methods*
  10. Ajit Singh V, Earnest Kunasingh D, Haseeb A, Yasin NF
    J Orthop Surg (Hong Kong), 2019 5 30;27(2):2309499019850313.
    PMID: 31138060 DOI: 10.1177/2309499019850313
    PURPOSE: Expandable endoprosthesis allows limb salvage in children with an option to leading a better life. However, the revision rate and implant-related complications impose as a limitation in the skeletal immature. This study investigates the functional outcomes and complications related to expandable endoprosthesis in our centre.

    MATERIALS AND METHODS: Twenty surviving patients with expandable endoprosthesis from 2006 till 2015 were scored using Musculoskeletal Tumour Society (MSTS) outcomes instrument and reviewed retrospectively for range of motion of respected joints, limb length discrepancy, number of surgeries performed, complications and oncological outcomes. Patients with less than 2 years of follow-up were excluded from this study.

    RESULTS: Forty-five percentage patients reached skeletal maturity with initial growing endoprosthesis and 25% of patients were revised to adult modular prosthesis. One hundred fifty-seven surgeries were performed over the 9-year period. The average MSTS score was 90.83%. The mortality rate was 10% within 5 years due to advanced disease. Infection and implant failure rate was 15% each. The event-free survival was 50% and overall survival rate was 90%.

    CONCLUSION: There is no single best option for reconstruction in skeletally immature. This study demonstrates a favourable functional and survival outcome of paediatric patients with expandable endoprosthesis. The excellent MSTS functional scores reflect that patients were satisfied and adjusted well to activities of daily living following surgery despite the complications.

    Matched MeSH terms: Prosthesis Design
  11. Al-Hashedi AA, Taiyeb-Ali TB, Yunus N
    Aust Dent J, 2016 06;61(2):208-18.
    PMID: 25966305 DOI: 10.1111/adj.12337
    BACKGROUND: Short dental implants can be an alternative to bone augmentation procedures at sites of reduced alveolar bone. Most studies on short implants are retrospective or multicentre reports that lack controlled and consistent comparison between different systems. This study aimed to compare clinical and radiographic outcomes of short implants in two different systems in the posterior mandible.

    METHODS: Twenty patients with two adjacent missing posterior teeth were recruited. Patients were assigned equally and randomly into two groups; Bicon(®) (6 or 8 mm) and Ankylos(®) (8 mm) implants. A two-stage surgical approach and single crowns were used for implant placement and loading. Outcomes included peri-implant clinical parameters, implant stability (Periotest values; PTVs) and peri-implant bone changes, which were assessed at baseline, 2, 6 and 12 months post-loading.

    RESULTS: No implant loss was encountered up to 12 months post-loading. No significant difference in the clinical or radiographic parameters was observed except for PTVs (p < 0.05) that was lower in Ankylos(®) implants.

    CONCLUSIONS: The use of short dental implants was associated with excellent 12 months clinical and radiographic outcomes. Ankylos(®) and Bicon(®) implants demonstrated similar peri-implant soft tissue and alveolar bone changes. However, Ankylos(®) implants demonstrated better implant stability at all evaluation intervals.

    Matched MeSH terms: Dental Prosthesis Design
  12. Abbas AA, Kim YJ, Song EK, Yoon TR
    J Arthroplasty, 2009 Oct;24(7):1144.e5-8.
    PMID: 18848418 DOI: 10.1016/j.arth.2008.09.008
    The causes of groin pain after total hip arthroplasty are numerous, and the condition itself is disabling. Therefore, it is imperative that the cause of the pain is identified and managed appropriately. We report a case where the patient had groin pain after total hip arthroplasty as a result of an oversized cementless acetabular component, which caused a breach in the anterior wall of the acetabulum. The anterior wall of the acetabulum was reconstructed with femoral head allograft, and the patient has been symptom free since.
    Matched MeSH terms: Prosthesis Design
  13. Ali RM, Degenhardt R, Zambahari R, Tresukosol D, Ahmad WA, Kamar Hb, et al.
    EuroIntervention, 2011 May;7 Suppl K:K83-92.
    PMID: 22027736 DOI: 10.4244/EIJV7SKA15
    Coronary lesions in diabetics (DM) are associated with a high recurrence following percutaneous coronary intervention (PCI), even after drug-eluting stent (DES) deployment. Encouraging clinical data of the drug-eluting balloon catheter (DEB) SeQuent Please warrant its investigation in these patients.
    Matched MeSH terms: Prosthesis Design
  14. Keun Seon J, Anwar Ayob K, Giun Noh M, Yeol Yang H
    Acta Orthop Traumatol Turc, 2024 Jan;58(1):68-72.
    PMID: 38525513 DOI: 10.5152/j.aott.2024.23115
    Oxidized zirconium (OxiniumTM) prostheses, made up of a metallic alloy of zirconium with a ceramic surface formed by oxidizing the outer layer, were developed as an alternative bearing surface to reduce polyethylene wear and decrease failure of total knee arthroplasty (TKA). We report a unique catastrophic failure of an Oxinium TKA with consequent accelerated wear and severe metallosis. Intraoperatively, we observed extensive wear grooving of the femoral component with exposure of the underlying silver layers and the complete wear of polyethylene on the medial side. Metallic debris had a peculiar arthrogram appearance, noted within the cut surface of the femur and tibia, indicative of the osteolysis that occurred, leading up to the failure of the implants. The histopathologic examination revealed a collection of macrophages with foreign-body reactions and black-pigmented metal-induced wear particles. Oxinium has clear benefits regarding superior wear properties; however, surgeons need to be aware that there is a risk of exposure to the underlying layers that may precede accelerated wear, deformation, and metallosis. Uncovering the deeper layers could result in the appearance of an arthrogram on plain radiographs. Early identification of polyethylene wear and prompt revision is crucial to avoid the rapid progression of subsequent metallosis and catastrophic implant failure, specifically when using oxidized zirconium components for TKA. To the best of our knowledge, this is the first report presenting a detailed histologic analysis to provide insight into the mechanisms of the failed Oxinium components.
    Matched MeSH terms: Prosthesis Design
  15. Rahman SA, Muhammad H, Haque S, Alam MK
    J Contemp Dent Pract, 2019 Feb 01;20(2):173-178.
    PMID: 31058631
    AIM: The aim of this study was to evaluate the changes in the peri-implant hard and soft tissues and implant stability and to assess the correlation of bone loss and peri-implant probing depth with implant stability.

    MATERIALS AND METHODS: Twenty-one patients with implants were included in this study and implants were assessed by resonance frequency analysis (RFA). Bone levels of the implants were assessed by measuring mesial and distal bone levels from the periapical radiograph, and soft tissue was assessed from probing depth using a periodontal probe. Implants were assessed for stability and probing depth at pre-loading, at 3 months and 6 months post-loading. RFA and probing depth were statistically compared from different time points. Correlation of probing depth and marginal bone loss with implant stability was also determined.

    RESULTS: The average change in implant stability quotient (ISQ) measurements from pre-loading to 6 months post-loading was found to be statistically significant (p <0.005). The average probing depth reduced from 1.767 mm at pre-loading to 1.671 mm at post-loading 3 months, and 1.600 mm at post-loading 6 months. At 6 months of function, radiographic examination yielded 0.786 mm mesial bone loss and 0.8 mm distal bone loss. It was found to be statistically significant (p <0.005) but within an acceptable range. No significant correlation was found between implant stability and bone loss; and implant stability and probing depth.

    CONCLUSION: The study revealed an increasing trend in implant stability values with the time that indicates successful osseointegration. Increasing mean values for mesial and distal bone loss were also found.

    CLINICAL SIGNIFICANCE: The success of dental implants is highly dependent on the quality of bone and implant-bone interface, i.e., osseointegration. The most important factors that influence the survival rate of an implant is initial stability. The present study found the changes in the peri-implant hard and soft tissues and implant stability. This article, while being a prospective study, may show the evidence of successful osseointegration by increasing trend in implant stability (RFA) values with time which can help to the clinician in the long-term management of implants.

    Matched MeSH terms: Dental Prosthesis Design
  16. El-Sayed AM, Hamzaid NA, Abu Osman NA
    Sensors (Basel), 2014;14(12):23724-41.
    PMID: 25513823 DOI: 10.3390/s141223724
    Alternative sensory systems for the development of prosthetic knees are being increasingly highlighted nowadays, due to the rapid advancements in the field of lower limb prosthetics. This study presents the use of piezoelectric bimorphs as in-socket sensors for transfemoral amputees. An Instron machine was used in the calibration procedure and the corresponding output data were further analyzed to determine the static and dynamic characteristics of the piezoelectric bimorph. The piezoelectric bimorph showed appropriate static operating range, repeatability, hysteresis, and frequency response for application in lower prosthesis, with a force range of 0-100 N. To further validate this finding, an experiment was conducted with a single transfemoral amputee subject to measure the stump/socket pressure using the piezoelectric bimorph embedded inside the socket. The results showed that a maximum interface pressure of about 27 kPa occurred at the anterior proximal site compared to the anterior distal and posterior sites, consistent with values published in other studies. This paper highlighted the capacity of piezoelectric bimorphs to perform as in-socket sensors for transfemoral amputees. However, further experiments are recommended to be conducted with different amputees with different socket types.
    Matched MeSH terms: Prosthesis Design*
  17. Eshraghi A, Osman NA, Gholizadeh H, Karimi M, Ali S
    Prosthet Orthot Int, 2012 Mar;36(1):15-24.
    PMID: 22269941 DOI: 10.1177/0309364611431625
    One of the main indicators of the suspension system efficiency in lower limb prostheses is vertical displacement or pistoning within the socket. Decreasing pistoning and introducing an effective system for evaluating pistoning could contribute to the amputees' rehabilitation process.
    Matched MeSH terms: Prosthesis Design
  18. Windecker S, Latib A, Kedhi E, Kirtane AJ, Kandzari DE, Mehran R, et al.
    N Engl J Med, 2020 03 26;382(13):1208-1218.
    PMID: 32050061 DOI: 10.1056/NEJMoa1910021
    BACKGROUND: Polymer-free drug-coated stents provide superior clinical outcomes to bare-metal stents in patients at high bleeding risk who undergo percutaneous coronary intervention (PCI) and are treated with 1 month of dual antiplatelet therapy. Data on the use of polymer-based drug-eluting stents, as compared with polymer-free drug-coated stents, in such patients are limited.

    METHODS: In an international, randomized, single-blind trial, we compared polymer-based zotarolimus-eluting stents with polymer-free umirolimus-coated stents in patients at high bleeding risk. After PCI, patients were treated with 1 month of dual antiplatelet therapy, followed by single antiplatelet therapy. The primary outcome was a safety composite of death from cardiac causes, myocardial infarction, or stent thrombosis at 1 year. The principal secondary outcome was target-lesion failure, an effectiveness composite of death from cardiac causes, target-vessel myocardial infarction, or clinically indicated target-lesion revascularization. Both outcomes were powered for noninferiority.

    RESULTS: A total of 1996 patients at high bleeding risk were randomly assigned in a 1:1 ratio to receive zotarolimus-eluting stents (1003 patients) or polymer-free drug-coated stents (993 patients). At 1 year, the primary outcome was observed in 169 of 988 patients (17.1%) in the zotarolimus-eluting stent group and in 164 of 969 (16.9%) in the polymer-free drug-coated stent group (risk difference, 0.2 percentage points; upper boundary of the one-sided 97.5% confidence interval [CI], 3.5; noninferiority margin, 4.1; P = 0.01 for noninferiority). The principal secondary outcome was observed in 174 patients (17.6%) in the zotarolimus-eluting stent group and in 169 (17.4%) in the polymer-free drug-coated stent group (risk difference, 0.2 percentage points; upper boundary of the one-sided 97.5% CI, 3.5; noninferiority margin, 4.4; P = 0.007 for noninferiority).

    CONCLUSIONS: Among patients at high bleeding risk who received 1 month of dual antiplatelet therapy after PCI, use of polymer-based zotarolimus-eluting stents was noninferior to use of polymer-free drug-coated stents with regard to safety and effectiveness composite outcomes. (Funded by Medtronic; ONYX ONE ClinicalTrials.gov number, NCT03344653.).

    Matched MeSH terms: Prosthesis Design
  19. Urban P, Meredith IT, Abizaid A, Pocock SJ, Carrié D, Naber C, et al.
    N Engl J Med, 2015 Nov 19;373(21):2038-47.
    PMID: 26466021 DOI: 10.1056/NEJMoa1503943
    BACKGROUND: Patients at high risk for bleeding who undergo percutaneous coronary intervention (PCI) often receive bare-metal stents followed by 1 month of dual antiplatelet therapy. We studied a polymer-free and carrier-free drug-coated stent that transfers umirolimus (also known as biolimus A9), a highly lipophilic sirolimus analogue, into the vessel wall over a period of 1 month.
    METHODS: In a randomized, double-blind trial, we compared the drug-coated stent with a very similar bare-metal stent in patients with a high risk of bleeding who underwent PCI. All patients received 1 month of dual antiplatelet therapy. The primary safety end point, tested for both noninferiority and superiority, was a composite of cardiac death, myocardial infarction, or stent thrombosis. The primary efficacy end point was clinically driven target-lesion revascularization.
    RESULTS: We enrolled 2466 patients. At 390 days, the primary safety end point had occurred in 112 patients (9.4%) in the drug-coated-stent group and in 154 patients (12.9%) in the bare-metal-stent group (risk difference, -3.6 percentage points; 95% confidence interval [CI], -6.1 to -1.0; hazard ratio, 0.71; 95% CI, 0.56 to 0.91; P<0.001 for noninferiority and P=0.005 for superiority). During the same time period, clinically driven target-lesion revascularization was needed in 59 patients (5.1%) in the drug-coated-stent group and in 113 patients (9.8%) in the bare-metal-stent group (risk difference, -4.8 percentage points; 95% CI, -6.9 to -2.6; hazard ratio, 0.50; 95% CI, 0.37 to 0.69; P<0.001).
    CONCLUSIONS: Among patients at high risk for bleeding who underwent PCI, a polymer-free umirolimus-coated stent was superior to a bare-metal stent with respect to the primary safety and efficacy end points when used with a 1-month course of dual antiplatelet therapy. (Funded by Biosensors Europe; LEADERS FREE ClinicalTrials.gov number, NCT01623180.).
    Matched MeSH terms: Prosthesis Design
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