Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): Guidelines for medical 3D printing and appropriateness for clinical scenarios

Este número da revista Cadernos de Estudos Sociais estava em organização quando fomos colhidos pela morte do sociólogo Ernesto Laclau. Seu falecimento em 13 de abril de 2014 surpreendeu a todos, e particularmente ao editor Joanildo Burity, que foi seu orientando de doutorado na University of Essex, Inglaterra, e que recentemente o trouxe à Fundação Joaquim Nabuco para uma palestra, permitindo que muitos pudessem dialogar com um dos grandes intelectuais latinoamericanos contemporâneos. Assim, buscamos fazer uma homenagem ao sociólogo argentino publicando uma entrevista inédita concedida durante a sua passagem pelo Recife, em 2013, encerrando essa revista com uma sessão especial sobre a sua trajetória

The virtual human face – superimposing the simultaneously captured 3D photorealistic skin surface of the face on the untextured skin image of the CBCT Scan

The aim of this study was to evaluate the impact of simultaneous capture of the three-dimensional (3D) surface of the face and cone beam computed tomography (CBCT) scan of the skull on the accuracy of their registration and superimposition. 3D facial images were acquired in 14 patients using the Di3d (Dimensional Imaging, UK) imaging system and i-CAT CBCT scanner. One stereophotogrammetry image was captured at the same time as the CBCT and another one hour later. The two stereophotographs were then individually superimposed over the CBCT using VRmesh. Seven patches were isolated on the final merged surfaces. For the whole face and each individual patch; maximum and minimum range of deviation between surfaces, absolute average distance between surfaces, and standard deviation for the 90th percentile of the distance errors were calculated. The superimposition errors of the whole face for both captures revealed statistically significant differences (P=0.00081). The absolute average distances in both separate and simultaneous captures were 0.47mm and 0.27mm, respectively. The level of superimposition accuracy in patches from separate captures ranged between 0.3 and 0.9mm, while that of simultaneous captures was 0.4mm. Simultaneous capture of Di3d and CBCT images significantly improved the accuracy of superimposition of these image modalities

3D-printing techniques in a medical setting : a systematic literature review

Background: Three-dimensional (3D) printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. This paper summarizes the literature on surgical 3D-printing applications used on patients, with a focus on reported clinical and economic outcomes. Methods: Three major literature databases were screened for case series (more than three cases described in the same study) and trials of surgical applications of 3D printing in humans. Results: 227 surgical papers were analyzed and summarized using an evidence table. The papers described the use of 3D printing for surgical guides, anatomical models, and custom implants. 3D printing is used in multiple surgical domains, such as orthopedics, maxillofacial surgery, cranial surgery, and spinal surgery. In general, the advantages of 3D-printed parts are said to include reduced surgical time, improved medical outcome, and decreased radiation exposure. The costs of printing and additional scans generally increase the overall cost of the procedure. Conclusion: 3D printing is well integrated in surgical practice and research. Applications vary from anatomical models mainly intended for surgical planning to surgical guides and implants. Our research suggests that there are several advantages to 3D- printed applications, but that further research is needed to determine whether the increased intervention costs can be balanced with the observable advantages of this new technology. There is a need for a formal cost-effectiveness analysis

Innovation in prediction planning for anterior open bite correction

This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical correction of a case

Physical and statistical shape modelling in craniomaxillofacial surgery: a personalised approach for outcome prediction

Orthognathic surgery involves repositioning of the jaw bones to restore face function and shape for patients who require an operation as a result of a syndrome, due to growth disturbances in childhood or after trauma. As part of the preoperative assessment, three-dimensional medical imaging and computer-assisted surgical planning help to improve outcomes, and save time and cost. Computer-assisted surgical planning involves visualisation and manipulation of the patient anatomy and can be used to aid objective diagnosis, patient communication, outcome evaluation, and surgical simulation. Despite the benefits, the adoption of three-dimensional tools has remained limited beyond specialised hospitals and traditional two-dimensional cephalometric analysis is still the gold standard. This thesis presents a multidisciplinary approach to innovative surgical simulation involving clinical patient data, medical image analysis, engineering principles, and state-of-the-art machine learning and computer vision algorithms. Two novel three-dimensional computational models were developed to overcome the limitations of current computer-assisted surgical planning tools. First, a physical modelling approach – based on a probabilistic finite element model – provided patient-specific simulations and, through training and validation, population-specific parameters. The probabilistic model was equally accurate compared to two commercial programs whilst giving additional information regarding uncertainties relating to the material properties and the mismatch in bone position between planning and surgery. Second, a statistical modelling approach was developed that presents a paradigm shift in its modelling formulation and use. Specifically, a 3D morphable model was constructed from 5,000 non-patient and orthognathic patient faces for fully-automated diagnosis and surgical planning. Contrary to traditional physical models that are limited to a finite number of tests, the statistical model employs machine learning algorithms to provide the surgeon with a goal-driven patient-specific surgical plan. The findings in this thesis provide markers for future translational research and may accelerate the adoption of the next generation surgical planning tools to further supplement the clinical decision-making process and ultimately to improve patients’ quality of life

Virtual Surgical Planning in Craniomaxillofacial surgery: A Structured Review

Craniomaxillofacial (CMF) surgery is a challenging and very demanding field that involves the treatment of congenital and acquired conditions of the face and head. Due to the complexity of the head and facial region, various tools and techniques were developed and utilized to aid surgical procedures and optimize results. Virtual Surgical Planning (VSP) has revolutionized the way craniomaxillofacial surgeries are planned and executed. It uses 3D imaging computer software to visualize and simulate a surgical procedure. Numerous studies were published on the usage of VSP in craniomaxillofacial surgery. However, the researchers found inconsistency in the previous literature which prompted the development of this review. This paper aims to provide a comprehensive review of the findings of the studies by conducting an integrated approach to synthesize the literature related to the use of VSP in craniomaxillofacial surgery. Twenty-nine related articles were selected as a sample and synthesized thoroughly. These papers were grouped assigning to the four subdisciplines of craniomaxillofacial surgery: orthognathic surgery, reconstructive surgery, trauma surgery and implant surgery. The following variables – treatment time, the accuracy of VSP, clinical outcome, cost, and cost-effectiveness – were also examined. Results revealed that VSP offers advantages in craniomaxillofacial surgery over the traditional method in terms of duration, predictability and clinical outcomes. However, the cost aspect was not discussed in most papers. This structured literature review will thus provide current findings and trends and recommendations for future research on the usage of VSP in craniomaxillofacial surgery

Total Temporomandibular Joint Replacement and Simultaneous Orthognathic Surgery Using Computer-Assisted Surgery

Background: Disorders of the temporomandibular joint (TMJ) are frequent and are usually associated with other disorders of the facial skeleton. Surgery might be needed to correct TMJ anatomy and function and, in cases where pathologies coexist, a two-stage corrective surgery might be needed. However, the current fashion of single-stage procedures is feasible with the aid of new technologies such as computer-assisted surgery (CAS). This is a step forward toward performing complex procedures such as a TMJ replacement with simultaneous orthognathic surgery. CAS allows designing patient-fitted prosthesis and more predictable and accurate surgeries. Moreover, intraoperative development can be controlled in real time with intraoperative navigation, and postoperative results can be measured and compared afterwards. Aims: The primary purpose of this article is to present the protocol used in our institution for orthognathic surgery associated with unilateral and bilateral TMJ replacement with patient-fitted prostheses guided with CAS. Materials and methods: We present two cases to illustrate our protocol and its results. Results: In the first case, the difference in millimeters between planning and surgical outcomes was 1.72 mm for the glenoid component and 2.16 mm for the condylar prosthesis; for the second case, differences in the right side were 2.59 mm for the glenoid component and 2.06 mm for the ramus, and in the left side, due to the anatomy the difference was a little greater, without clinical significance Conclusion: Combined surgery of the midface and mandible with total TMJ replacement is feasible and beneficial for the patient. CAS facilitates the planning and design of custom-fit prosthesis and execution of these procedures.Fil: Gomez, Natalia Lucia. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Boccalatte, Luis Alejandro. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Lopez Ruiz, Águeda. No especifíca;Fil: Nassif, María Gabriela. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Figari, Marcelo Fernando. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Ritacco, Lucas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Hospital Italiano. Instituto de Medicina Traslacional E Ingenieria Biomedica. - Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional E Ingenieria Biomedica.; Argentin

The precision of orthognathic surgery with customized titanium plates: a systematic review

The objective of this work was to do a systematic review to access the precision of orthognathic surgery with customized titanium plates in relation to the outcome of virtual planning. This is a systematic review with a protocol registered in the PROSPERO database, which followed the PRISMA guideline and Cochrane recommendations. Six databases and two gray literature repositories were used as sources of research articles. The research protocol was registered in PROSPERO (CRD42019133769). Descriptive clinical studies that performed orthognathic surgery using custom titanium plates were included. The risk of bias of the selected studies was assessed by “The Joanna Briggs Institute Critical Appraisal tools for use in Systematic Reviews Checklist for Case Series”. Of the 11,916 studies initially identified, 7 met the eligibility criteria and were included in this review. The studies were case series published between 2015 and 2019. Most of the studies (57%) had a low risk of bias, while only one had a high risk of bias. The total sample included 74 patients with 63 bimaxillary surgeries and 11 unimaxillary surgeries. It can be concluded thar all studies showed acceptable precision within previously established clinical parameters. Although the eligible articles assessed the precision of the orthognathic surgery with respect to virtual planning, the wide variability of evaluation methodologies made it impossible to calculate a combined precision measure. Nevertheless, all studies have suggested that the use of custom titanium plates in orthognathic surgery had high precision compared to the outcome of virtual planning.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorDissertação (Mestrado)O objetivo deste trabalho foi realizar uma revisão sistemática para avaliar a precisão da cirurgia ortognática com placas de titânio customizadas em relação ao planejamento virtual. Trata-se de uma revisão sistemática com protocolo registrado na base de dado PROSPERO, que seguiu o guideline PRISMA e recomendaçãoes Cochrane. Seis bases de dados (Embase, LILACS, PubMed, SciELO, Scopus, Web of Science) foram utilizadas como fonte primária de pesquisa. E duas bases (OpenThesis e OpenGrey) para capturar parte da literatura cinzenta. Foi realizado registro do protocolo de pesquisa junto ao PROSPERO (CRD42019133769). Foram incluídos estudos clínicos descritivos que realizaram cirurgia ortognática com o uso de placas de titânio customizadas, sem restrição de ano, idioma e status de publicação. O risco de viés dos estudos selecionados foi avaliado pela ferramenta “The Joanna Briggs Institute Critical Appraisal tools for use in JBI Systematic Reviews Checklist for Case Series”. Dos 11.916 estudos identificados inicialmente, somente sete preencheram os critérios de elegibilidade e foram incluídos nessa revisão. Os estudos são séries de casos publicados entre 2015 e 2019. A maioria dos estudos (57%) apresentou risco de viés baixo, enquanto apenas um estudo apresentou alto risco de viés. A amostra total incluiu 74 pacientes, com 63 cirurgias bimaxilares, e 11 cirurgias unimaxilares. Conclui-se que todos os estudos mostraram precisão aceitável dentro de parâmetros clínicos previamente estabelecidos. Embora todos os artigos elegíveis para esta revisão sistemática tenham comparado a precisão da cirurgia ortognática em relação ao planejamento virtual, a grande variabilidade das metodologias de avaliação impossibilitou o cálculo de uma medida de precisão combinada. Apesar disso, todos estudos sugeriram que a utilização de placas de titânio customizadas em cirurgia ortognática obteve alta precisão em relação ao planejamento virtual