Search

file: :Users/pieter-janverhelst/Library/Mobile Documents/com apple CloudDocs/Medical Library/Mendeley/Janssens et al/Oral and Maxillofacial Surgery Cases/Janssens et al. - 2020 - Oral and Maxillofacial Surgery Cases Craniopharyngioma with malignant transformation A case report.pdf:pdf keywords: Craniopharyngioma,Malignant,Maxillofacial surgery, ispartof: Oral and Maxillofacial Surgery Cases vol:6 issue:3 status: published

In this work we couple an IGA-BEM solver for 2D lifting flows with the viscous model in X-Foil [1], a vintage but still widely used software tool for the design and analysis of subsonic airfoils, towards deeper integration of the isogeometric concept in 2D flow models that incorporate boundary-layer corrections. The formulation of the exterior potential-flow problem reduces to a Boundary Integral Equation (BIE) for the associated velocity potential. Adopting the approach presented in [3], the resulting BIE is handled by an IGA-BEM method, combining: (i) A generic B-splines parametric modeler for generating hydrofoil shapes, using a set of 8 design-oriented parameters; (ii) The very same basis of the geometric representation for representing the velocity potential, and (iii) Collocation at the Greville abscissas of the knot vector of the hydrofoil’s B-splines representation, appropriately enhanced to accommodate the null-pressure jump Kutta condition at the trailing edge. For the viscous part of the solution, the two-equation model of X-Foil [2] is employed. X-Foil’s inviscid solver is “circumvented” and inviscid isogeometric parameters are sent to its viscous component, namely the integral momentum and kinetic energy shape parameter equations presented in [2]. The derived coupled system is tested for NACA4412 and NACA0012 airfoils and the output lift and drag coefficients for different angle of attacks are compared to experimental data, uncoupled X-Foil results and one-way coupling results obtained [4] via the software tool PABLO [5]. The so-resulting coupled system can be used in airfoil/hydrofoil shape optimisation algorithms with a variety of optimisation criteria such as maximum lift coefficient, maximum lift-over-drag-ratio, minimum deviation of the airfoil/hydrofoil area from a reference area, etc. REFERENCES [1] Drela, M. (1989) “XFOIL: An analysis and design system for low Reynolds number airfoils”, MIT, Massachusetts, USA. [2] Drela, M., Giles, M. (1987) “Viscous – inviscid analysis of transonic and low Reynolds number airfoils”, AIAA Journal, vol. 25(10), pp. 1347 – 1355. [3] Kostas, K.V., Ginnis, A.I., Politis, C.G., Kaklis, P.D. (2017) “Shape-optimization of 2D hydrofoils using an Isogeometric BEM solver”, Computer Aided Design, vol. 82, pp. 79-87. [4] Kostas, K.V., Ginnis, A.-A.I, Politis, C.G., Kaklis P.D. (2017) “Shape-optimization of 2D hydrofoils using one-way coupling of an IGA-BEM solver with a boundary-layer model”, Coupled Problems 2017, VII International Conference on Coupled Problems in Science and Engineering, June 12-14, 2017, Rhodes (GR).

Background: The orbital floor (OrF) and infraorbital rim (IOR) repair in cases of complete destruction is challenging mainly due to the fact that the defect length cannot be measured. The aim of the current study is to develop a method of calculating the Orf length by using the gender and the lengths of the medial, superior and lateral orbital walls (OrW) of the same orbit. Material and methods: Ninety-seven (59 male and 38 female) European adult dry skulls were classified according to age: 20–39, 40–59 and 60 years and above. The length of each OrW was measured by using the direct distance between the optic foramen and a landmark in each orbital rim. Results: A side asymmetry was detected for the lengths of the inferior, superior and medial OrW. Although a gender dimorphism was detected, no correlation with the age was found. Using the Stepwise multiple regression analysis two formulas were developed, one for the right and one for the left OrF with coefficient of determination R2 0.43 and 0.57, respectively. Conclusions: The proposed formulas represent a simple, applicable and individualized method to calculate the OrF linear length in cases of complete destruction of the IOR and OrF, with accuracy and without the use of expertise material. Such data may improve the surgery planning of orbital floor fractures and complex orbital reconstructions. © 2018

Post-traumatic trigeminal neuropathy is a debilitating condition that may occur after dental, oral, and maxillofacial procedures. In this retrospective case series study, we describe the clinical and patient reported outcomes on 13 patients with trigeminal nerve injuries that occurred after various interventions who underwent surgical exploration and subsequent surgical treatment with buccal fat nerve wrapping. We observed both positive and negative neuropathic symptoms preoperatively. Postoperative pain and quality of life was measured with the Brief Pain Inventory. Medication use was recorded pre- and postoperatively. Surgical exploration of the inferior alveolar or lingual nerve was performed in all patients. The median time between the injury and the exploration surgery was 21 weeks. The actual treatment of the lesion depended on its nature. Upon closing the wound, buccal fat was wrapped around the damaged nerve to facilitate nerve regeneration and provide protection. Overall improvements in negative and/or positive symptoms was observed in 12 patients during a mean follow-up time of 36 months. All patients that experienced pain before surgery reported pain reduction, and 2 patients reported complete pain resolution. On the BPI questionnaire, six patients reported persistent pain. In conclusion, surgery and the use of buccal fat grafts successfully reduced positive and negative symptoms, including pain symptoms, after iatrogenic trigeminal nerve injuries. In addition, medication use was reduced postoperatively. Future research should evaluate whether the use of a fat graft might provide a more protective nerve regeneration environment, compared to conventional treatments. Keywords: ispartof: Journal of Clinical Case Reports vol:9 issue:5 status: published

Combining Iso-Geometric analysis (IGA) with Boundary Element Methods (BEM) for inviscid lifting flows imposes a number of difficulties. Firstly, an IGABEM collocation scheme has to take into account the tangent-plane discontinuity occurring along the trailing edge (TE). More important, the scheme has to handle the non-linear Kutta condition, securing continuity of the normal velocity and pressure through the a-priori unknown wake, a force-free boundary surface emanating from TE. In this presentation we shall review the status of our work towards developing a pair of IGABEM collocation schemes for computing steady lifting flows around 2D and 3D bodies , e.g., hydrofoils, marine propellers; [1,2]. In the latter case, the ansatz functions are inherited from T-spline representations which are free from singularities occurring, e.g., at the tip of a propeller blade, when NURBS are used. REFERENCES [1] Kostas, K.V., Ginnis, A.-A. I., Politis, C.G., Kaklis, P.D, “Shape-optimization of 2D hydrofoils using an Isogeometric BEM solver”, Computer-Aided Design, vol. 82, pp. 79-87, (2017). [2] Chouliaras, S.P., Kaklis, P.D., Ginnis, A.-A.I., Kostas, K.V., Politis, C.G., “An IGA-BEM method for the open-water marine propeller flow problem”, International Conference on Isogeometric Analysis, Pavia (IT), 11-13 September 2017.

Trigeminal neuralgia is characterized by unilateral pain in the region supplied by the sensory distribution of the fifth cranial nerve. Pharmacologic therapy is an adequate initial treatment option in 75% of patients. When the Jannetta surgical operation is not available or not indicated and when conservative treatment fails to relieve the pain or the medication has to be discontinued because of side effects, one of the remaining surgical options is cryosurgery in the peripherally distributed nerves that emanate from the trigeminal nerve. This technical note describes a perioperative method for exposing and mobilizing the inferior alveolar nerve (IAN) from its bony canal. This approach provided easy access to infratemporal fossa structures during cryotherapy. This technique represented a further development of the technique previously described by the authors. This method ensured direct visualization of the IAN and wide access to theinfratemporal fossa during IAN cryotherapy. © 2018 American Association of Oral and Maxillofacial Surgeons

Purpose: This observational case registry study was designed to describe the natural history of cancer patients with medication-related osteonecrosis of the jaw (ONJ) and evaluate the ONJ resolution rate. Methods: Adults with a diagnosis of cancer and with a new diagnosis of ONJ were enrolled and evaluated by a dental specialist at baseline and every 3 months for 2 years and then every 6 months for 3 years until death, consent withdrawal, or loss to follow-up. The primary endpoint was the rate and time course of ONJ resolution. Secondary endpoints included frequency of incident ONJ risk factors, ONJ treatment patterns, and treatment patterns of antiresorptive agents for subsequent ONJ. Results: Overall, 327 patients were enrolled; 207 (63%) were continuing on study at data cutoff. Up to 69% of evaluable patients with ONJ had resolution or improvement during the study. ONJ resolution (AAOMS ONJ staging criteria) was observed in 114 patients (35%); median (interquartile range) time from ONJ onset to resolution was 7.3 (4.5–11.4) months. Most patients (97%) had received antiresorptive medication before ONJ development, 9 patients (3%) had not; 68% had received zoledronic acid, 38% had received denosumab, and 10% had received pamidronate (56% had received bisphosphonates only, 18% had received denosumab only, and 21% had exposure to both). Conclusions: These results are consistent with those observed in clinical trials evaluating skeletal-related events in patients with advanced malignancy involving bone. Longer follow-up will provide further information on ONJ recurrence and resolution rates between medically and surgically managed patients. © 2017, The Author(s).

The MHC class II region in humans is highly polymorphic. Each MHC molecule is formed by an α and a β chain, produced by different genes, creating an antigen-binding groove. In the groove there are several pockets into which antigens anchor and fit. The affinity of this fitting determines the recognition specificity of a given peptide. Here, based on our previous results about the association of MHC class II with the WNV disease, we examined the role of the binding pockets of HLA-DPA1, -DQA1 and-DRB1 in the severe form of the disease. In HLA-DQA1, variants in all pockets 1, 6 and 9 were found to be associated with either protection and/or susceptibility to neuroinvasion caused by WNV. Similarly, pockets 7, 9 and 10 in HLA-DRB1 were associated with severe disease. Protein modeling of these molecules revealed structural and functional differences among alleles with opposite roles concerning the development of the disease. Different amino acids in positions α52 and α66 (HLADQA1) significantly influenced the peptide binding while DYWLR/EFA combination (HLADRB1) was associated with neuronal damage. Further studies could help us understand the selectivity of pocket variants in order to create suitable peptides for an effective response. © 2018 Sarri et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

This work combines an Isogeometric (IGA) Boundary-Analysis-Method (BEM) solver for potential flows with a boundary-layer correction model for developing and testing a framework for the shape optimization of hydrofoils placed in low-speed viscous flow.The formulation of the exterior potential-flow problem reduces to a Boundary-Integral Equation (BIE) for the associated velocity potential exploiting the null-pressure jump Kutta condition at the trailing edge. Adopting the approach presented in [1], the numerical solution of the resulting BIE is performed by an IGA-BEM method, combining: (i)a generic B-splines parametric modeler for generating hydrofoil shapes, using a set of eight parameters, (ii)the very same basis of the geometric representation for representing the velocity potential, and (iii)collocation at the Greville abscissas of the knot vector of the hydrofoil’s B-splines representation, appropriately enhanced so that the null-pressure jump Kutta condition at the trailing edge.As for the boundary-layer correction model, we adopt the one-way coupled approach proposed in [2], where the effect of the boundary layer thickness is neglected and one single iteration is performed. More accurately, the external tangential velocity is inherited from the inviscid model with the condition of vanishing-normal velocity on the airfoil’s surface and then fed to the boundary-layer model. The drag coefficient can then be obtained using the Squire-Young formula [3], which in effect computes the momentum deficit as a function of the outcome of the boundary-layer calculations at the trailing edge.In fine, the optimization environment is developed based on the geometric parametric modeler for the hydrofoil, the IGA-BEM solver which feeds the above boundary-layer correction and an optimizer employing a controlled elitist genetic algorithm. Its performance is tested via shape optimization examples involving a variety of criteria such as, maximum lift coefficient, maximum lift-over-drag-ratio, minimum deviation of the hydrofoil area from a reference area, etc.