Αρχειοθήκη ιστολογίου

Τετάρτη 30 Μαρτίου 2022

Comparison of stress distribution between zirconia/alloy endocrown and CAD/CAM multi-piece zirconia post-crown: three-dimensional finite element analysis

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Abstract

Objectives

This study aimed to evaluate a digital multi-piece zirconia post-crown to restore a mandibular second molar with extensive coronal loss and limited restoration space, and to compare the stress distribution between endocrowns made of zirconia or alloy and CAD/CAM multi-piece zirconia post-crowns.

Material and methods

Four three-dimensional finite element analysis models of a mandibular second molar with extensive coronal loss and limited restoration space were created as follows: (A) intact molar; (B) zirconia endocrown restored molar; (C) multi-piece post-crown restored-molar with tapered nail; (D) multi-piece post-crown restored molar with T-shaped nail. Models C and D were divided into two subgroups according to the material type: C1/D1, zirconia; C2/D2, NiCr alloy. The maximum modified von Mises failure criterion (mvM) stresses were calculated, and the stress distribution was recorded to analyze the effects of the restoration and material types on the biomechanical properties of dentin and prosthesis.

Results

The maximum mvM stress of dentin in model B (33.80 MPa) was lower compared with models C (C1, 37.81 MPa; C2, 36.36 MPa) and D (D1, 36.34 MPa; D2, 34.97 MPa) under vertical load, but the opposite was observed under oblique load. The highest mvM stress was concentrated in the nail region located in the root canal, and the T-shaped nail values were greater than the tapered nail, whereas model D with T-shaped nail showed a lower mvM stress level in dentin compared with Model C with tapered nail.

Conclusions

The digital multi-piece zirconia post-crown is a potential approach to restore mandibular second molars with extensive coronal loss and limited restoration space.

Clinical relevance

The digital multi-piece zirconia post-crown has potential to restore mandibular second molars with extensive coronal loss and limited restoration space using an innovative approach.

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The implicated clinical factors for outcomes in 304 patients with salivary duct carcinoma: Multi‐institutional retrospective analysis in Japan

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Abstract

Background

Salivary duct carcinoma (SDC) is a high-grade salivary malignancy that frequently occurs as the carcinomatous component of carcinoma ex pleomorphic adenoma. We herein examined the clinical factors affecting outcomes in a large cohort of SDC.

Methods

We selected 304 SDC cases and investigated clinical characteristics and the factors affecting outcomes.

Results

The median age of the cases examined was 68 years, the most common primary site was the parotid gland (238 cases), and there was a male predominance (M/F = 5:1). Outcomes were significantly worse when the primary tumor site was the minor salivary glands (SG) than when it was the major SG. Outcomes were also significantly worse in pN(+) cases (161 cases) than in pN0 cases, particularly those with a metastatic lymph node number ≥11. The cumulative incidence of relapse and distant metastases was significantly higher in stage IV cases than in stage 0–III cases.

Conclusions

The absolute number of lymph node metastases, higher stages, and the minor SG as the primary tumor site were identified as factors affecting the outcome of SDC.

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From a Slave to a Surgeon: David Kearney McDonogh, the First Black Otolaryngologist

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Otolaryngology–Head and Neck Surgery, Ahead of Print.
David McDonogh, born into chattel slavery in Louisiana in the early 1800s, accomplished the unfathomable by becoming the first Black otolaryngologist in the United States of America. With tireless determination and profound intellect, Dr McDonogh surmounted immeasurable adversity along his improbable journey to freedom and success as an eye, ear, nose, and throat doctor in New York. His doctorate in medicine was posthumously awarded to his great-great-granddaughter in 2018 by the Columbia University Vagelos College of Physicians and Surgeons. In this History of Otolaryngology piece, we share his extraordinary story.
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Systemic Steroids for Otolaryngology–Head and Neck Surgery Disorders: An Evidence-Based Primer for Clinicians

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Otolaryngology–Head and Neck Surgery, Ahead of Print.
ObjectiveTo offer pragmatic, evidence-informed guidance on the use of systemic corticosteroids (SCS) for common otolaryngologic disorders.Data SourcesPubMed, Cochrane Library, and American Academy of Otolaryngology–Head and Neck Surgery Foundation clinical practice guidelines.Review MethodsA comprehensive search of published literature through November 2021 was conducted on the efficacy of SCS, alone or in combination with other treatments, for managing disorders in otolaryngology and the subdisciplines. Clinical practice guidelines, systematic reviews, and randomized controlled trials, when available, were preferentially retrieved. Interventions and outcomes of SCS use were compiled to generate summary tables and narrative synthesis of findings.ConclusionsEvidence on the effectiveness of SCS varies widely across otolaryngology disorders. High-level evidence supports SCS use for Bell's palsy, sinonasal polyposis, a nd lower airway disease. Conversely, evidence is weak or absent for upper respiratory tract infection, eustachian tube dysfunction, benign paroxysmal positional vertigo, adenotonsillar hypertrophy, or nonallergic rhinitis. Evidence is indeterminate for acute laryngitis, acute pharyngitis, acute sinusitis, angioedema, chronic rhinosinusitis without polyps, Ménière's disease, postviral olfactory loss, postoperative nerve paresis/paralysis, facial pain, and sudden sensorineural hearing loss.Implications for PracticeClinicians should bring an evidence-informed lens to SCS prescribing to best counsel patients regarding the risks, anticipated benefits, and limited data on long-term effects. Alternate routes of corticosteroid administration—such as sprays, drops, inhalers, and intralesional injections—may be preferable for many disorders, particularly those that are self-limited or require a prolonged duration of therapy. Prudent use of SCS reduces the risk of medication-related ad verse effects. Clinicians who are conversant with high-level evidence can achieve optimal outcomes and stewardship when prescribing SCS.
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A Novel External Auditory Canal Squamous Cell Carcinoma Cell Line Sensitive to CDK4/6 Inhibition

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Otolaryngology–Head and Neck Surgery, Ahead of Print.
ObjectiveTo characterize cell line CAE606 derived from a squamous cell carcinoma (SCC) of the external auditory canal (EAC) and to show its usefulness as a model for testing candidate therapeutic agents.Study DesignPreclinical translational research.SettingBiomedical research institute.MethodsThe cell line was initiated from a moderately differentiated T2N0M0 EAC SCC. We studied its histologic and genetic features as well as growth and invasion parameters. Sensitivity to cell CDK4/6 cell cycle inhibitor palbociclib was analyzed.ResultsCAE606 cells expressed heavy molecular weight cytokeratin, p63, and vimentin. The population doubling time was 25.8 hours, and the cells showed fast collective cell migration in a wound-healing assay. Short tandem repeat analysis confirmed it to be derived from the primary tumor of the patient. Next-generation sequencing revealed alterations in cell cycle regulation genes, including inact ivating mutations in CDKN2A and TP53 and high-level amplification of CCND1 and EGFR. CAE606 showed a strong decrease of phospo-Rb expression upon exposure to the CDK4/6 inhibitor palbociclib, causing significant growth inhibition with an IC50 of 0.46 µM.ConclusionThis is the first report of a stable EAC SCC cell line. Its genetic features make it a useful tool for preclinical testing of new therapeutic agents for EAC SCC, particularly those targeting cell cycle regulation in combination with radio- and chemotherapy or other specific signaling pathway inhibitors.
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Subclonal heterogeneity sheds light on the transformation trajectory in IGLV3-21R110 chronic lymphocytic leukemia

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Blood Cancer Journal, Published online: 30 March 2022; doi:10.1038/s41408-022-00650-4

Subclonal heterogeneity sheds light on the transformation trajectory in IGLV3-21R110 chronic lymphocytic leukemia
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Comparison of the Osteogenic Effectiveness of an Autogenous Demineralized Dentin Matrix and Bio-Oss® in Bone Augmentation: A Systematic Review and Meta-analysis

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Publication date: Available online 29 March 2022

Source: British Journal of Oral and Maxillofacial Surgery

Author(s): Yanfei Li, Wanhang Zhou, Peiyi Li, Qipei Luo, Anqi Li, Xinchun Zhang

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Cancer Risk Associated with Continuous Positive Airway Pressure: A National Study

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Objective

In 2021 the U.S. FDA issued a Class 1 safety recall notice for specific devices due to a risk of carcinogen exposure. The objective of this study was to evaluate reports of cancer linked to CPAP devices to understand implications for the field of sleep medicine.

Methods

Cases of cancer involving CPAP devices were retrieved from the MAUDE database from 2014 to 2021 and analyzed with descriptive statistics.

Results

A total of 2571 patient injuries were associated with CPAP. Reports of cancer (n = 209; 4.62%) were the second most commonly documented patient problem associated with CPAP, although 1950 (43.13%) patients had a device problem without an associated injury. Of the 209 cancer cases associated with CPAP, 200 (95.7%) of the adverse event reports were received by the FDA in 2021. There were 174 (9.15%) descriptions of the CPAP polyurethane sound abatement foam degrading in association with a cancer diagnosis, but degradation was more commonly not associated with malignancy (n = 1728; 90.85%). Other frequently documented CPAP device problems included broken devices (n = 279; 6.92%), fire (n = 182; 4.51%), and patient–device incompatibility (n = 144; 3.57%).

Conclusion

Malignancy associated with CPAP devices has been reported; however, future studies are required to establish causation. Given 95.7% of those documented cases were reported in 2021, otolaryngologists should be prepared to discuss the risks of carcinogenesis associated with CPAP. The otolaryngology community should also be aware of the potential bandwagon effect and the implications for CPAP compliance.

Level of Evidence

4 Laryngoscope, 2022

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Key Points on Functional Rhinoplasty Patient Evaluation

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Abstract

Purpose of Review

The goal of this review is to discuss the key points in the evaluation of patients for functional nasal airway surgery to help optimize outcomes.

Recent Findings

Development of the clinical practice guideline for rhinoplasty was a recent effort to guide perioperative care and workup of patients undergoing rhinoplasty. This guideline highlighted the importance of patient reported outcome measures (PROMs) in evaluating surgical outcomes. There has also been an increase in publications regarding intervention in the pediatric population. Finally, there has been more work into the exact mechanics of nasal airway obstruction and lateral wall insufficiency.

Summary

Functional rhinoplasty lacks clear objective tests to help guide surgery. PROMs are important in evaluating surgical outcomes and advances in technology such as computational fluid dynamics, and virtual surgical planning will hopefully provide insight into airflow patterns and where surgical intervention should be focused to maximize patient outcomes.

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Anatomical variations in the relationship between the spinal accessory nerve and internal jugular vein: a systematic review and meta-analysis

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The relationship between the spinal accessory nerve and internal jugular vein is important for modified neck dissection surgery. Therefore, the aim of this review was to investigate variations in this relationship. Through a search of the PubMed, Scopus, Web of Science, LILACS, and SciELO databases, the review authors collected anatomical data for inclusion in a meta-analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Four relationship patterns were identified and classified: type 1, the nerve lies superficial to the vein; type 2, the nerve lies deep to the vein; type 3, the nerve crosses the branches of the vein; type 4, the nerve splits and its branches pass around the vein.
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