A Procedure for Cutting Guides Design in Maxillofacial Surgery: A Case-Study

2019 ◽  
pp. 301-310
Author(s):  
L. Ulrich ◽  
F. Baldassarre ◽  
F. Marcolin ◽  
S. Moos ◽  
S. Tornincasa ◽  
...  
Keyword(s):  
Maxillofacial Surgery ◽  
Cutting Guides

scholarly journals Rapid prototyping: applications in oral and maxillofacial surgery

2020 ◽  
Vol 27 (1) ◽  
pp. 11
Author(s):  
Francesco Giovacchini ◽  
Massimiliano Gilli ◽  
Valeria Mitro ◽  
Gabriele Monarchi ◽  
Caterina Bensi ◽  
...  
Keyword(s):  
Rapid Prototyping ◽  
Maxillofacial Surgery ◽  
Cancer Recurrence ◽  
Oral And Maxillofacial Surgery ◽  
Aesthetic Outcome ◽  
Virtual Planning ◽  
Free Fibula ◽  
Cutting Guides ◽  
Stereolithographic Models

This article documents four mandibular reconstructions performed using free fibula flaps. CT scan DICOM (Digital Imaging and COmmunication in Medicine) files were obtained in order to print stereolithographic models of the mandible, and in one case cutting guides for fibular osteotomies. One case study details the treatment a cancer recurrence on a right emimandibulectomy. Because of a lack of access to previous CT scans, the left part of the mandible was mirrored to obtain an accurate 3D model. In one case, due to the young age of the woman, a double barrel fibula flap was used. All cases resulted in satisfactory chewing function and aesthetic outcome, with no flap failures. The report concludes that Virtual Planning and Rapid Prototyping are helpful as they reduce costs and intraoperative times while simultaneously improving surgical precision.

scholarly journals Imaging, Virtual Planning, Design, and Production of Patient-Specific Implants and Clinical Validation in Craniomaxillofacial Surgery

2012 ◽  
Vol 5 (3) ◽  
pp. 137-143 ◽  
Author(s):  
Per Dérand ◽  
Lars-Erik Rännar ◽  
Jan-M Hirsch
Keyword(s):  
Additive Manufacturing ◽  
Treatment Plan ◽  
Maxillofacial Surgery ◽  
Bone Substitutes ◽  
Patient Specific ◽  
Virtual Design ◽  
Patient Specific Implants ◽  
Cutting Guide ◽  
Ablative Surgery ◽  
Cutting Guides

The purpose of this article was to describe the workflow from imaging, via virtual design, to manufacturing of patient-specific titanium reconstruction plates, cutting guide and mesh, and its utility in connection with surgical treatment of acquired bone defects in the mandible using additive manufacturing by electron beam melting (EBM). Based on computed tomography scans, polygon skulls were created. Following that virtual treatment plans entailing free microvascular transfer of fibula flaps using patient-specific reconstruction plates, mesh, and cutting guides were designed. The design was based on the specification of a Compact UniLOCK 2.4 Large (Synthes®, Switzerland). The obtained polygon plates were bent virtually round the reconstructed mandibles. Next, the resections of the mandibles were planned virtually. A cutting guide was outlined to facilitate resection, as well as plates and titanium mesh for insertion of bone or bone substitutes. Polygon plates and meshes were converted to stereolithography format and used in the software Magics for preparation of input files for the successive step, additive manufacturing. EBM was used to manufacture the customized implants in a biocompatible titanium grade, Ti6Al4V ELI. The implants and the cutting guide were cleaned and sterilized, then transferred to the operating theater, and applied during surgery. Commercially available software programs are sufficient in order to virtually plan for production of patient-specific implants. Furthermore, EBM-produced implants are fully usable under clinical conditions in reconstruction of acquired defects in the mandible. A good compliance between the treatment plan and the fit was demonstrated during operation. Within the constraints of this article, the authors describe a workflow for production of patient-specific implants, using EBM manufacturing. Titanium cutting guides, reconstruction plates for fixation of microvascular transfer of osteomyocutaneous bone grafts, and mesh to replace resected bone that can function as a carrier for bone or bone substitutes were designed and tested during reconstructive maxillofacial surgery. A clinically fit, well within the requirements for what is needed and obtained using traditional free hand bending of commercially available devices, or even higher precision, was demonstrated in ablative surgery in four patients.

Three-Dimensional Custom-Made Surgical Guides in Facial Feminization Surgery: Prospective Study on Safety and Accuracy

2021 ◽  
Author(s):  
Pierre Tawa ◽  
Nicolas Brault ◽  
Vlad Luca-Pozner ◽  
Laurent Ganry ◽  
Ghassen Chebbi ◽  
...  
Keyword(s):  
Maxillofacial Surgery ◽  
Three Dimensional ◽  
Cerebrospinal Fluid Leak ◽  
Mandibular Angle ◽  
Virtual Planning ◽  
Surgical Guides ◽  
Sinus Wall ◽  
Custom Made ◽  
Cutting Guides ◽  
Fluid Leak

Abstract Background Facial feminization surgery (FFS) includes several osseous modifications of the forehead, mandible and chin, procedures which require precision in order to provide the patient with a satisfactory result. Mispositioned osteotomies can lead to serious complications and bad aesthetic outcomes. Surgical cutting guides are commonly used in plastic and maxillofacial surgery to improve safety and accuracy. Yet, there is no report in the literature on the clinical application of cutting guides in FFS. Objectives The aim of this paper is to assess the safety and accuracy of custom surgical cutting guides in FFS procedures. Methods A prospective follow-up of forty-five patients regarding FFS with preoperative virtual planning and 3D custom-made surgical guides for anterior frontal sinus wall setback, mandibular angle reduction and/or osseous genioplasty was conducted. Accuracy (superimposing preoperative data on postoperative data by global registration with a 1 mm margin of error), safety (intradural intrusion for the forehead procedures and injury of the infra alveolar nerve for chin and mandibular angles) and patient satisfaction were assessed. Results A total of 133 procedures were documented. There was no cerebrospinal fluid leak on the forehead procedures nor any infra alveolar nerve or tooth root injury on both chin and mandibular angle operations (safety, 100%). Accuracy was 90.80 % on the forehead (n=25), 85.72% on the mandibular angles (n=44) and 96.20% on the chin (n=26). An overall satisfaction of 94.40% was recorded. Conclusions Custom-made surgical cutting guides could be a safe and accurate tool for forehead, mandibular angles and chin procedures for FFS.

scholarly journals Orbital dermoid and epidermoid cysts: Case study

2010 ◽  
Vol 138 (11-12) ◽  
pp. 755-759 ◽  
Author(s):  
Dragan Veselinovic ◽  
Dragan Krasic ◽  
Ivan Stefanovic ◽  
Aleksandar Veselinovic ◽  
Zoran Radovanovic ◽  
...  
Keyword(s):  
Dermoid Cyst ◽  
Diagnostic Procedure ◽  
Maxillofacial Surgery ◽  
Cranial Nerves ◽  
Nerve Compression Syndrome ◽  
Epidermoid Cysts ◽  
Compression Syndrome ◽  
Temporal Quadrant ◽  
Inflammation Signs

Introduction. Dermoid and epidermoid cysts of the orbit belong to choristomas, tumours that originate from the aberrant primordial tissue. Clinically, they manifest as cystic movable formations mostly localized in the upper temporal quadrant of the orbit. They are described as both superficial and deep formations with most frequently slow intermittent growth. Apart from aesthetic effects, during their growth, dermoid and epidermoid cysts can cause disturbances in the eye motility, and in rare cases, also an optical nerve compression syndrome. Case Outline. In this paper, we described a child with a congenital orbital dermoid cyst localized in the upper-nasal quadrant that was showing signs of a gradual enlargement and progression. The computerized tomography revealed a cyst of 1.5-2.0 cm in size. At the Maxillofacial Surgery Hospital in Nis, the dermoid cyst was extirpated in toto after orbitotomy performed by superciliary approach. Postoperative course was uneventful, without inflammation signs, and after two weeks excellent functional and aesthetic effects were achieved. Conclusion. Before the decision to treat the dermoid and epidermoid cysts operatively, a detailed diagnostic procedure was necessary to be done in order to locate the cyst precisely and determine its size and possible propagation into the surrounding periorbital structures. Apart from cosmetic indications, operative procedures are recommended in the case of cysts with constant progressions, which cause the pressure to the eye lobe, lead to motility disturbances and indirectly compress the optical nerve and branches of the cranial nerves III, IV and VI.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

Culture and the plasticity of perception

2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann
Keyword(s):  
Cultural Context ◽  
Sensory Experience ◽  
Cultural Learning ◽  
The World

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.

Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic
Keyword(s):  
Temporal Reasoning ◽  
Higher Order ◽  
Important Case ◽  
Human Cognition ◽  
Relational Reasoning ◽  
Dual Systems ◽  
First Order ◽  
Reasoning System ◽  
Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

Sociocultural memory development research drives new directions in gadgetry science

2019 ◽  
Vol 42 ◽  
Author(s):  
Penny Van Bergen ◽  
John Sutton
Keyword(s):  
Episodic Memory ◽  
Autobiographical Memory ◽  
Developmental Psychology ◽  
Cross Cultural ◽  
Memory Development ◽  
Development Research ◽  
Cultural Research ◽  
New Directions ◽  
Cross Cultural Research

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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