Polyoxymethylene as Material for Removable Partial Dentures-A Literature Review and Illustrating Case Report.
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ABSTRACT:
SUBMITTER: Schierz O
PROVIDER: S-EPMC8038064 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD), to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE) model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO) technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT), potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM) for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption.
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Project description:We report a case of a 55 years old women who present a ALK associated renal cell carcinoma, with 3p deletion and measling of TFE3 expression. With CGH analysis and FISH we identify the rearrangment of ALK with TPM3
2017-03-24 | GSE96980 | GEO
Project description:BackgroundAppropriate load distribution among the supporting elements is essential for the long-term success of implant-assisted removable partial dentures; however, there is little information available on load distribution.PurposeThis study aimed to evaluate the effect of implant location on load distribution in implant-assisted removable partial dentures by reviewing in vitro models and finite-element analysis studies.Materials and methodsEnglish-language studies which examined the load distribution of implant-assisted removable partial dentures and were published between January 2001 and October 2022 were extracted from PubMed, ScienceDirect, and Scopus online databases, and manual searching. Two reviewers selected the articles based on the predetermined inclusion and exclusion criteria, followed by data extraction and analysis.ResultsForty-seven studies were selected after evaluating the titles and abstracts of 264 articles; two were identified manually. After screening the text, 12 studies were included: six in vitro model experiments and six finite-element analysis studies. All included studies used a mandibular free-end missing model (Kennedy Class I or II). The influence of implant location on load distribution to the abutment tooth, implant, and mucosa under the denture base was summarized in three cases: implant at the premolar, first molar, and second molar region. Due to differences in the measurement method of load distribution and loading condition to the denture, the results differed among the studies.ConclusionsThe implant location in implant-assisted removable partial dentures can affect load distribution to the supporting elements, such as the abutment tooth, implant, and mucosa under the denture base.
| S-EPMC10509086 | biostudies-literature
Project description:ObjectivesThe present pilot study analyzed two abutment types (a retentive ball and a non-retentive dome) in implant-assisted removable partial dentures (IARPDs) on 6 mm short implants with respect to clinical, radiological, and patient-reported outcomes (PROs), during the first year.Materials and methodsTwo implants were placed bilaterally in mandibular molar sites, converting existing free-end removable partial dentures (RPDs) to IARPDs. Twelve subjects were randomized to initially receive either the dome (Group A, n = 6) or the ball abutment (Group B, n = 6). After eight weeks, the abutments were exchanged. After another 8 weeks, the participants were given the choice of one of the abutments. Mean values and standard deviations (SD) were calculated, and random-effect linear regression analyses were applied to analyze marginal bone level alterations and PROs (α < .05).ResultsTwelve participants were included in the study; however, one dropout occurred. Patient ratings increased significantly in both study groups. The majority of the participants (82%) ultimately chose the ball abutment. The implant survival rate was 100%, and the success rate was 90.9% twelve months after implant placement (mean peri-implant bone-loss: -1.2; SD: 0.6 mm) without a statistically significant difference between the study groups, in terms of clinical- and radiological outcomes.ConclusionPlacing 6 mm short implants at mandibular molar sites of RPD wearers seems to be a viable treatment option, based on this investigation with a short-term follow-up. Although only minor differences between the two abutments were observed, patients seem to prefer the ball over the dome abutment.
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Project description:BACKGROUND:Lipodystrophy syndromes are rare disorders of variable body fat loss associated with potentially serious metabolic complications. Familial partial lipodystrophy (FPLD) is mostly inherited as an autosomal dominant disorder. Renal involvement has only been reported in a limited number of cases of FPLD. Herein, we present a rare case of proteinuria associated with type 4 FPLD, which is characterized by a heterozygous mutation in PLIN1 and has not been reported with renal involvement until now. CASE PRESENTATION:A 15-year-old girl presented with insulin resistance, hypertriglyceridaemia, hepatic steatosis and proteinuria. Her glucose and glycated haemoglobin levels were within normal laboratory reference ranges. A novel heterozygous frameshift mutation in PLIN1 was identified in the patient and her mother. The kidney biopsy showed glomerular enlargement and focal segmental glomerulosclerosis under light microscopy; the electron microscopy results fit with segmental thickening of the glomerular basement membrane. Treatment with an angiotensin-converting enzyme inhibitor (ACEI) decreased 24-h protein excretion. CONCLUSIONS:We report the first case of proteinuria and renal biopsy in a patient with FPLD4. Gene analysis demonstrated a novel heterozygous frameshift mutation in PLIN1 in this patient and her mother. Treatment with ACEI proved to be beneficial.
| S-EPMC5946515 | biostudies-literature
Project description:BackgroundIncisor loss constitutes a strong aesthetic and psychologic traumatism for the patient and it remains a challenging situation for the dental practitioner because of the necessity to rapidly replace the lacking tooth. Various therapeutic procedures have been proposed to replace the incisor concerned, for example by using a removable partial denture. However, the manufacturing of such a denture with classical procedures is often subject to processing errors and inaccuracies. The computer-aided design and computer-aided manufacturing (CAD-CAM) technology could represent a good alternative, but it is currently difficult because of the lack of dental softwares able to design easily immediate removable partial dentures.Case presentationA 30-year- patient complained about pain caused by a horizontally and vertically mobile maxillary right central incisor. After all options were presented, extraction of the traumatized incisor was decided due to its very poor prognosis, and the patient selected the realization of a removable denture for economic reasons. The present paper proposes an innovative procedure for immediate removable denture, based on the use of an intraoral scanner, CAD with two different softwares used sequentially, and CAM with a 5-axis machine.ConclusionsWe show in this report that associating an intraoral scanner and CAD-CAM technology can be extended to immediate dentures manufacturing, which could be a valuable procedure for dental practitioners and laboratories, and also for patients.
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Project description:Myopericytoma (MPC) is a benign soft tissue tumor that develops from perivascular myoid cells and is part of the perivascular tumor group. MPC most commonly occurs in the subcutaneous soft tissues of the extremities, while intracranial MPC is remarkably rare. Herein, we report the case of a 45-year-old woman with myopericytoma who had a 2-week history of recurrent dizziness. Magnetic resonance imaging (MRI) revealed an irregular mass in the pons, with nodular enhancement of the mass on contrast-enhanced scans. The mass was considered a vascular lesion and was highly suspected to be a hemangioblastoma, prompting surgical intervention for the patient. The postoperative pathological report corrected the initial diagnosis, hemangioblastoma, to MPC. Intracranial MPC is extremely rare and there are no detailed imaging sources for this condition; furthermore, MPC occurrence in the pons has not been reported previously. This report presents the etiological characteristics intracranial MPC as visualized through MRI data alongside a comparative discussion on other reported diagnoses that resemble MPC. The case findings will provide a more widespread understanding for radiologists regarding the differential diagnosis of intracranial blood-rich supply lesions.
| S-EPMC9148993 | biostudies-literature
Project description:Objectives To describe a unique case report of a patient who had partial hearing preservation after translabyrinthine (TL) removal of a vestibular schwannoma (VS). Study Design Case report. Methods The patient's chart was reviewed for hearing levels before and after surgery. Preoperative magnetic resonance imaging (MRI) was compared with postoperative MRI for determination of completeness of tumor removal. The literature on hearing preservation after TL resection is reviewed. Results A 42-year-old woman underwent a TL removal of a VS. The patient's preoperative pure tone average (PTA) was 70 dB and word recognition score (WRS) was 40%. Postoperatively, the patient was able to hear ambient noise in the surgical ear. Her bone conduction PTA was 70 dB, but the WRS score dropped to 2%. One year later, she continues to hear ambient noise and sound in the operative ear. Discussion This is the fifth reported case of partial hearing preservation after TL VS resection. It suggests that by preserving the vestibule and the fluids within the vestibule when possible, there maybe enough residual auditory neural structures for a traditional cochlear implant to benefit such a patient. In addition, preserving the incus when possible may help maintain air conduction to help patients with sound localization.
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Project description:Objective: The aim of the present study is to explore the clinical and genetic characteristics of 3p deletion syndrome to improve clinicians' understanding of the disease. Methods: The clinical manifestations, process of diagnosis and treatment, and genetic characteristics of an individual case of 3p deletion syndrome were analyzed. CNKI, Wanfang Data, and the Biomedical Literature Database (PubMed) were searched. The search time limit, using "3p deletion syndrome" and "BRPF1" as keywords, was from the creation of the database up to June 2020. Related data were reviewed. Results: The proband was a male child with general developmental and intellectual disabilities, special facial features and congenital heart disease. The child was the parents' first pregnancy and first born. Gene microarray analysis showed a 10.095 Mb deletion in the 3p26.3-p25.3 region, resulting in a heterozygous mutation of the BRPF1 gene; thus, the patient was diagnosed with 3p deletion syndrome. At the time of diagnosis, the child was 1 year of age and was responding to comprehensive rehabilitation training. A total of 29 well-documented cases were found in the literature, of which 19 cases had an onset within 1 year of birth, and mainly manifested with mental and motor development disabilities and abnormal facial features, with different gene deletions, depending on the size and location of the 3p deletion. Conclusion: The genetic test results of the child in this study indicated a heterozygous deletion of the BRPF1 gene on the short arm of chromosome 3, which was a unique feature of this study, since it was rarely mentioned in other reports of 3p deletion syndrome. The clinical phenotype of this syndrome is complex as it can include intellectual and motor development backwardness, low muscle tone, certain abnormal facial features (low hairline, bilateral ptosis, widely spaced eyes, a forward nose, left ear auricle deformity, a high-arched palate, a small jaw), and the deformation of systems such as the gastrointestinal tract and the urinary tract malformation or symptoms of epilepsy. As clinical manifestations can be relatively mild, the syndrome is easy to miss or misdiagnose. Clinical workers need to be aware of this disease when they find that children have special features, such as stunted growth, low muscle tone or ptosis, and it needs to be diagnosed through genetic testing. Most children are able to develop certain social skills after rehabilitation treatment.
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