Objective: To determine how mechanical stability changes in the lower lateral cartilage (LLC) after varying degrees of cephalic resection in a porcine cartilage nasal tip model.
Methods: Alar cartilage was harvested from fresh porcine crania (n = 14) and sectioned to precisely emulate a human LLC in size and dimension. Flexural mechanical analysis was performed both before and after cephalic trims of 0 (control), 4, and 6 mm. Cantilever deformation tests were performed on the LLC models at 3 locations (4, 6, and 8 mm from the midline), and the integrated reaction force was measured. An equivalent elastic modulus of the crura was calculated assuming that the geometry of the LLC model approximated a modified single cantilever beam. A 3-dimensional finite element model was used to model the stress distribution of the prescribed loading conditions for each of the 3 types of LLC widths.
Results: A statistically significant decrease (P = .02) in the equivalent elastic modulus of the LLC model was noted at the most lateral point at 8 mm and only when 4 mm of the strut remained (P = .05). The finite element model revealed that the greatest internal stresses was at the tip of the nose when tissue was flexed 8 mm from the midline.
Conclusion: Our results provide the mechanical basis for suggested clinical guidelines stating that a residual strut of less than 6 mm can lead to suboptimal cosmetic results owing to poor structural support of the overlying skin soft-tissue envelope by an overly resected LLC.
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http://dx.doi.org/10.1001/archfacial.2011.1354 | DOI Listing |
Arch Gynecol Obstet
January 2025
Department of Obstetrics and Gynecology, Ulsan University Hospital, University of Ulsan, College of Medicine, 25 Daehakbyeongwon-ro, Dong-gu, Ulsan, 44033, South Korea.
Background: The primary treatment for cervical insufficiency is cervical cerclage (mechanical support) with vaginal progesterone (biochemical support). Cerclage is a surgical procedure that mechanically increases the tensile capacity of the cervix. Therefore, it is necessary to analyse the effects of cerclage from a mechanical point of view.
View Article and Find Full Text PDFAm J Orthod Dentofacial Orthop
January 2025
Department of Orthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. Electronic address:
Introduction: The objective of this study was to evaluate the effects of the miniplate application sites in the maxilla and the applied force vector changes during skeletally supported facemask application in adolescent patients with unilateral cleft lip and palate (UCLP) using finite element model (FEM) analysis.
Methods: A FEM was obtained from a cone-beam computed tomography image of a 12-year-old female patient with UCLP. Miniplates were placed on 3 different sites of the maxilla; 500 g of advancement force was applied bilaterally, parallel (0°), and downward (-30°) to the occlusal plane.
Am J Med Genet A
January 2025
Massachusetts General Hospital, Boston, Massachusetts, USA.
Prader-Willi syndrome (PWS) is a genetic disorder associated with baseline respiratory impairment caused by multiple contributing etiologies. While this may be expected to increase the risk of severe COVID-19 infections in PWS patients, survey studies have suggested paradoxically low disease severity. To better characterize the course of COVID-19 infection in patients with PWS, this study analyses the outcomes of hospitalizations for COVID-19 among patients with and without PWS.
View Article and Find Full Text PDFJ Microsc
January 2025
Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK.
Electron backscatter diffraction (EBSD) has developed over the last few decades into a valuable crystallographic characterisation method for a wide range of sample types. Despite these advances, issues such as the complexity of sample preparation, relatively slow acquisition, and damage in beam-sensitive samples, still limit the quantity and quality of interpretable data that can be obtained. To mitigate these issues, here we propose a method based on the subsampling of probe positions and subsequent reconstruction of an incomplete data set.
View Article and Find Full Text PDFBiophys J
January 2025
Department of Physics, Northeastern University, Boston, MA, 02115, USA. Electronic address:
Binuclear ruthenium complexes have been investigated for potential DNA-targeted therapeutic and diagnostic applications. Studies of DNA threading intercalation, in which DNA base pairs must be broken for intercalation, have revealed means of optimizing a model binuclear ruthenium complex to obtain reversible DNA-ligand assemblies with the desired properties of high affinity and slow kinetics. Here, we used single-molecule force spectroscopy to study a binuclear ruthenium complex with a longer semi-rigid linker relative to the model complex.
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