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This study was designed to evaluate the accuracy of a novel computer-designed and selectively laser sintered surgical guide for flapless dental implant placement in the edentulous jaw. Fifty dental implants were placed in 11 patients with at least 1 totally edentulous jaw. Initially, cone-beam computed tomography (CBCT) was performed in each patient to define the virtual position of the dental implants based on the assessment of bone availability and the proposed dental prosthesis. After virtual planning, 3D surgical guides were printed using selective laser sintering. CBCT was repeated after the surgery, and the pre- and postoperative images were overlapped in computer-assisted design software to compare the planned and actual positions of the dental implants using a 1-sample t test. The mean ± angular standard deviation between the long axes of the planned and final dental implant positions was 4.58° ± 2.85°; the linear deviation in the coronal position was 0.87 ± 0.49 mm and in the apical region of the dental implants was 1.37 ± 0.69 mm. These differences were statistically significant (P < .001). The proposed modifications reduced the deviations, resulting in an improvement in the technique. We were able to place implants and temporary prostheses using the present protocol, taking into account the differences between the planned and final positions of the dental implants.
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Implantes Dentales , Arcada Edéntula , Cirugía Asistida por Computador , Diseño Asistido por Computadora , Computadores , Tomografía Computarizada de Haz Cónico/métodos , Implantación Dental Endoósea/métodos , Humanos , Imagenología Tridimensional/métodos , Arcada Edéntula/diagnóstico por imagen , Arcada Edéntula/cirugía , Rayos Láser , Planificación de Atención al Paciente , Cirugía Asistida por Computador/métodosRESUMEN
BACKGROUND: Nerve injuries are debilitating, leading to long-term motor deficits. Remyelination and axonal growth are supported and enhanced by growth factor and cytokines. Combination of nerve guidance conduits (NGCs) with adipose-tissue-derived multipotent mesenchymal stromal cells (AdMSCs) has been performing promising strategy for nerve regeneration. METHODS: 3D-printed polycaprolactone (PCL)-NGCs were fabricated. Wistar rats subjected to critical sciatic nerve damage (12-mm gap) were divided into sham, autograft, PCL (empty NGC), and PCL + MSCs (NGC multi-functionalized with 106 canine AdMSCs embedded in heterologous fibrin biopolymer) groups. In vitro, the cells were characterized and directly stimulated with interferon-gamma to evaluate their neuroregeneration potential. In vivo, the sciatic and tibial functional indices were evaluated for 12 weeks. Gait analysis and nerve conduction velocity were analyzed after 8 and 12 weeks. Morphometric analysis was performed after 8 and 12 weeks following lesion development. Real-time PCR was performed to evaluate the neurotrophic factors BDNF, GDNF, and HGF, and the cytokine and IL-10. Immunohistochemical analysis for the p75NTR neurotrophic receptor, S100, and neurofilament was performed with the sciatic nerve. RESULTS: The inflammatory environment in vitro have increased the expression of neurotrophins BDNF, GDNF, HGF, and IL-10 in canine AdMSCs. Nerve guidance conduits multi-functionalized with canine AdMSCs embedded in HFB improved functional motor and electrophysiological recovery compared with PCL group after 12 weeks. However, the results were not significantly different than those obtained using autografts. These findings were associated with a shift in the regeneration process towards the formation of myelinated fibers. Increased immunostaining of BDNF, GDNF, and growth factor receptor p75NTR was associated with the upregulation of BDNF, GDNF, and HGF in the spinal cord of the PCL + MSCs group. A trend demonstrating higher reactivity of Schwann cells and axonal branching in the sciatic nerve was observed, and canine AdMSCs were engrafted at 30 days following repair. CONCLUSIONS: 3D-printed NGCs multi-functionalized with canine AdMSCs embedded in heterologous fibrin biopolymer as cell scaffold exerted neuroregenerative effects. Our multimodal approach supports the trophic microenvironment, resulting in a pro-regenerative state after critical sciatic nerve injury in rats.
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Células Madre Mesenquimatosas , Animales , Perros , Regeneración Nerviosa , Impresión Tridimensional , Ratas , Ratas Wistar , Células de Schwann , Nervio CiáticoRESUMEN
Bone is a dynamic tissue that can always rebuild itself by modeling and remodeling to maintain functionality. This tissue is responsible for several vital functions in the body, such as providing structural support for soft tissues and the body, being the central region of hematopoiesis in human adults, and contributing to mineral homeostasis. Besides, it has an innate ability of auto-regeneration when damaged. All of these processes involve several molecular cues related to biochemical and mechanical stimulus. However, when the lesion is complicated or too big, it is necessary to intervene surgically, which may not effectively solve the problem. Bone tissue engineering seeks to provide resources to resolve these clinical issues and has been advancing in recent years, presenting promising devices for bone tissue repair. The understanding of some important biofactors and bone stem-cells influence might be crucial for an effective regenerative medicine, since bone is one of the most transplanted tissues. So, the purpose of this article is to provide an overview of the bone tissue, including the role of stem cells and some of the bioactive molecules associated with these processes. Finally, we will suggest future directions for bone tissue engineering area that might be helpful in order to produce biomimetic bone substitutes that become a real alternative to translational medicine.
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Materiales Biocompatibles , Huesos/citología , Huesos/fisiología , Fracturas Óseas/fisiopatología , Ingeniería de Tejidos/métodos , Animales , Remodelación Ósea/fisiología , Humanos , Células MadreRESUMEN
The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has spread through more than 180 countries, leading to diverse health systems overload around the world. Because of the high number of patients and the supply chain disruption, it generated a shortage of medical devices and personal protective equipment. In this context, initiatives from the additive manufacturing community emerged to fight the lack of devices. Diverse designs were produced and are currently being used in hospitals by patients and health workers. However, as some devices must follow strict standards, these products may not fulfill these standards. Therefore, to ensure the user's health, there is a need for understanding each device, their usage, and standards. This study reviews the use of additive manufacturing during COVID-19 pandemic. It gathers the source of several 3D printed devices such as face shields, face masks, valves, nasopharyngeal swabs, and others, discussing their use and regulatory issues. In this regard, the major drawbacks of the technology, addressed for the next pandemic scenario, are highlighted. Finally, some insights of the future of additive manufacturing during emergency are given and discussed.
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BACKGROUND: Cranial reconstruction surgery is a procedure used as an attempt to reestablish the cranial bone anatomy. This study evaluates the symptomatic and aesthetic improvement of patients with cranial defects secondary to decompressive craniectomies after cranial reconstruction with customized polymethyl methacrylate (PMMA) prostheses. Secondly, we aim to divide our experience in the production of these prostheses with a low-cost method. METHODS: A prospective study was carried out with patients submitted to cranioplasty at the Hospital da Restauração between 2014 and 2017. A total of 63 cranioplasties were performed using customized PMMA prosthesis produced by 3D impression molds. All patients underwent a functional and aesthetic evaluation questionnaire in the preoperative period and in the sixth postoperative month. RESULTS: Sixty-three patients underwent cranioplasty with a mean age of 33 years, ranging from 13 to 58 years, 55 males and 8 females. The mean area of the defect was 147 cm2. The mean postoperative follow-up of the patients was 21 months, ranging from 6 to 33 months. Fifty-five patients attended the 6-month postoperative consultation. All patients presented symptomatic improvement after reconstruction of the skull. The infection rate was 3.2%, 4.8% of extrusion, 1.6% of prosthesis fracture, 7.9% of extradural hematoma, 17.4% of reoperation, 5% of wound dehiscence, and 4.8% of removal of the prosthesis. CONCLUSION: Cranioplasty, with a customized PMMA prosthesis, improved the symptoms and aesthetic appearance of all operated patients. The use of prototypes to customize cranial prostheses facilitated the operative technique and allowed the recovery of a cranial contour very close to normal.
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This study verified the difference between two methods of forensic facial approximation (FFA) regarding recognition and resemblance rates. Three-dimensional models of skulls were obtained from computerized tomography (CT) scans of two subjects (targets). Two manual FFAs were performed for each target, by applying two different guidelines for the facial structures (what we called "American method" (AM) and "Combined method" (CM)). Unfamiliar assessors evaluated the sculptures by recognition and resemblance tests. The AM was that which allowed more correct responses of recognition and higher resemblance's scores for the male target (p < 0.001). Regarding guidelines for modeling characteristics of the face, the ones that are practical and easily performed for sculptures, such as the length of the anterior nasal spine multiplied by 3 for nose prediction, may offer better results in terms of resemblance.
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Cara/anatomía & histología , Antropología Forense/métodos , Cráneo/anatomía & histología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escultura , Adulto JovenRESUMEN
Facial soft tissue thicknesses (FSTT) are important guidelines for modeling faces from skull. Amid so many FSTT data, Forensic artists have to make a subjective choice of a dataset that best meets their needs. This study investigated the performance of four FSTT datasets in the recognition and resemblance of Brazilian living individuals and the performance of assessors in recognizing people, according to sex and knowledge on Human Anatomy and Forensic Dentistry. Sixteen manual facial approximations (FAs) were constructed using three-dimensional (3D) prototypes of skulls (targets). The American method was chosen for the construction of the faces. One hundred and twenty participants evaluated all FAs by means of recognition and resemblance tests. This study showed higher proportions of recognition by FAs conducted with FSTT data from cadavers compared with those conducted with medical imaging data. Targets were also considered more similar to FAs conducted with FSTT data from cadavers. Nose and face shape, respectively, were considered the most similar regions to targets. The sex of assessors (male and female) and the knowledge on Human Anatomy and Forensic Dentistry did not play a determinant role to reach greater recognition rates. It was possible to conclude that FSTT data obtained from imaging may not facilitate recognition and establish acceptable level of resemblance. Grouping FSTT data by regions of the face, as proposed in this paper, may contribute to more accurate FAs.
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Cara/anatomía & histología , Antropología Forense/métodos , Antropología Forense/normas , Brasil , Reconocimiento Facial , Femenino , Humanos , MasculinoRESUMEN
PURPOSE: The aim of this study is to present the development of a new technique to obtain 3D models using photogrammetry by a mobile device and free software, as a method for making digital facial impressions of patients with maxillofacial defects for the final purpose of 3D printing of facial prostheses. METHODS: With the use of a mobile device, free software and a photo capture protocol, 2D captures of the anatomy of a patient with a facial defect were transformed into a 3D model. The resultant digital models were evaluated for visual and technical integrity. The technical process and resultant models were described and analyzed for technical and clinical usability. RESULTS: Generating 3D models to make digital face impressions was possible by the use of photogrammetry with photos taken by a mobile device. The facial anatomy of the patient was reproduced by a *.3dp and a *.stl file with no major irregularities. 3D printing was possible. CONCLUSIONS: An alternative method for capturing facial anatomy is possible using a mobile device for the purpose of obtaining and designing 3D models for facial rehabilitation. Further studies must be realized to compare 3D modeling among different techniques and systems. CLINICAL IMPLICATION: Free software and low cost equipment could be a feasible solution to obtain 3D models for making digital face impressions for maxillofacial prostheses, improving access for clinical centers that do not have high cost technology considered as a prior acquisition.
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Teléfono Celular , Cara/anatomía & histología , Modelos Anatómicos , Fotogrametría/métodos , Impresión Tridimensional , Prótesis e Implantes , Humanos , Aplicaciones Móviles , Fotogrametría/instrumentaciónRESUMEN
OBJECTIVES: The objective of this study was to evaluate the variation of the orbital volume and the correlation with the magnitude of craniofacial advances as well as demonstrate its effectiveness through comparisons with normal levels of orbital volumes. INTRODUCTION: Syndromic craniofacial synostosis is characterized by cranial morphological alterations and hypoplasia of the midface that may result in obstructive sleep apnea and exorbitism; these effects are indications of surgical treatment. The gradual advancement of tissues is the surgical treatment to correct accentuated exorbitisms and jaw retrusions. METHODS: This was a retrospective study by review of medical records and tomographic examinations of 20 patients submitted to distraction osteogenesis between 2001 and 2012, who were divided into 2 groups: groups MB and LF with 11 and 9 patients, who underwent frontofacial or Le Fort III osteotomy. The orbit volume was measured with the InVesalius and Magics software, and facial advancements with Rhinoceros software. Statistical analyses were conducted using Student t test and analysis of variance. RESULTS: Patients' ages ranged from 6 to 29 years. Group MB showed an increase of 8.94 and 9.84 mm(3) in the right and left orbit volume variation, whereas group LF presented 5.70 and 5.77 mm(3). The average advancements in the right and left orbits were 11.36 ± 3.80 and 11.11 ± 3.45 mm in group LF, respectively, and 14.22 ± 4.12 and 14.48 ± 4.49 mm in group MB. CONCLUSIONS: Exorbitism was satisfactorily treated. The correlation was proportional in group LF and group MB. There was normalization of orbital volume compared with normal levels of orbital volumes.
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Disostosis Craneofacial/cirugía , Imagenología Tridimensional , Órbita/diagnóstico por imagen , Osteotomía Le Fort/métodos , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Disostosis Craneofacial/diagnóstico por imagen , Femenino , Humanos , Masculino , Órbita/cirugía , Tamaño de los Órganos , Estudios Retrospectivos , Adulto JovenRESUMEN
BACKGROUND: The uncoordinated activity of the superior and inferior parts of the lateral pterygoid muscle (LPM) has been suggested to be one of the causes of temporomandibular joint (TMJ) disc displacement. A therapy for this muscle disorder is the injection of botulinum toxin (BTX), of the LPM. However, there is a potential risk of side effects with the injection guide methods currently available. In addition, they do not permit appropriate differentiation between the two bellies of the muscle. Herein, a novel method is presented to provide intraoral access to the superior head of the human LPM with maximal control and minimal hazards. METHODS: Computational tomography along with digital imaging software programs and rapid prototyping techniques were used to create a rapid prototyped guide to orient BTX injections in the superior LPM. RESULTS: The method proved to be feasible and reliable. Furthermore, when tested in one volunteer it allowed precise access to the upper head of LPM, without producing side effects. CONCLUSIONS: The prototyped guide presented in this paper is a novel tool that provides intraoral access to the superior head of the LPM. Further studies will be necessary to test the efficacy and validate this method in a larger cohort of subjects.
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Modelos Biológicos , Boca/cirugía , Músculos Pterigoideos/cirugía , Disco de la Articulación Temporomandibular/cirugía , Trastornos de la Articulación Temporomandibular/cirugía , Tomografía Computarizada por Rayos X , Femenino , Humanos , Boca/diagnóstico por imagen , Músculos Pterigoideos/diagnóstico por imagen , Disco de la Articulación Temporomandibular/diagnóstico por imagen , Trastornos de la Articulación Temporomandibular/diagnóstico por imagenRESUMEN
BACKGROUND: In the international scientific literature, there are few studies that emphasize the presence or absence of hair in forensic facial reconstructions. There are neither Brazilian studies concerning digital facial reconstructions without hair, nor research comparing recognition tests between digital facial reconstructions with hair and without hair. The miscegenation of Brazilian people is considerable. Brazilian people, and, in particular, Brazilian women, even if considered as Caucasoid, may present the hair in very different ways: curly, wavy or straight, blonde, red, brown or black, long or short, etc. For this reason, it is difficult to find a correct type of hair for facial reconstruction (unless, in real cases, some hair is recovered with the skeletal remains). AIMS AND METHODS: This study focuses on the performance of three different digital forensic facial reconstructions, without hair, of a Brazilian female subject (based on one international database and two Brazilian databases for soft facial-tissue thickness) and evaluates the digital forensic facial reconstructions comparing them to photographs of the target individual and nine other subjects, employing the recognition method. A total of 22 assessors participated in the recognition process; all of them were familiar with the 10 individuals who composed the face pool. RESULTS AND CONCLUSIONS: The target subject was correctly recognized by 41% of the 22 examiners in the International Pattern, by 32% in the Brazilian Magnetic Resonance Pattern and by 32% in the Brazilian Fresh Cadavers Pattern. The facial reconstructions without hair were correctly recognized using the three databases of facial soft-tissue thickness. The observed results were higher than the results obtained using facial reconstructions with hair, from the same skull, which can indicate that it is better to not use hair, at least when there is no information concerning its characteristics.
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Cara/anatomía & histología , Cabello , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Brasil , Femenino , Antropología Forense , Humanos , Variaciones Dependientes del Observador , Fotograbar , Cráneo/anatomía & histología , Cráneo/diagnóstico por imagen , Programas Informáticos , Tomografía Computarizada por Rayos XRESUMEN
This chapter briefly describes the concepts underlying medical imaging reconstruction and the requirements for its integration with subsequent applications as BioCAD, rapid prototyping (RP), and rapid manufacturing (RM) of implants, scaffolds, or organs. As an introduction to the problem, principles related to data acquisition, enhancement, segmentation, and interpolation are discussed. After this, some available three-dimensional medical reconstruction software tools are presented. Finally, applications of these technologies are illustrated.
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Materiales Biomiméticos/química , Imagenología Tridimensional/métodos , Andamios del Tejido/química , Biomimética/métodos , Humanos , Imagenología Tridimensional/instrumentación , Modelos Anatómicos , Prótesis e Implantes , Programas Informáticos , Ingeniería de Tejidos/métodosRESUMEN
PURPOSE: In the operating room (OR) a touchless interface is an ideal solution since it does not demand any physical contact and still can provide the necessary control features in a cleansed and sterilized environment. METHODS: Using open-source software libraries and image processing techniques, we implemented a hand tracking and gesture recognition system based on the Kinect device that enables surgeon to successfully touchlessly navigate through the image in the intraoperative setting through a personal computer. We used the InVesalius software, which provides high-quality 3D reconstruction of medical images. RESULTS: Computed tomography data were intraoperatively fruitfully accessed through a simple and cheap solution in 4 tumor enucleations in 3 male patients in whom elective nephron-sparing surgeries were performed for small non-exophitic tumors. Mean tumor length was 2.7 cm (2.1, 2.7, 2.9 and 3.1 cm), and real-time ultrasound was not necessary for intraoperative identification in 3 of 4 endorenal tumors. All pathological reports revealed renal cell carcinoma, Fuhrman grade I, and negative inked surgical margins. No intra- or postoperative complication was reported. CONCLUSIONS: For the first time in the literature, a touchless user interface solution applying the Kinect device showed to be very efficient and enabled a low-cost and accurate control of the software InVesalius intraoperative, just using hand gestures. It can be used with any mouse-controlled software, opening an avenue for potential applications in many other areas, such as data visualization, augmented reality, accessibility, and robotics. The further validation and advancement of this technology are underway.
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Gestos , Procesamiento de Imagen Asistido por Computador/métodos , Monitoreo Intraoperatorio/métodos , Procedimientos Quirúrgicos Urológicos , Interfaz Usuario-Computador , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/cirugía , Diseño de Equipo , Humanos , Procesamiento de Imagen Asistido por Computador/instrumentación , Procesamiento de Imagen Asistido por Computador/normas , Neoplasias Renales/patología , Neoplasias Renales/cirugía , Masculino , Monitoreo Intraoperatorio/instrumentación , Monitoreo Intraoperatorio/normas , Quirófanos , Robótica , Diseño de Software , Esterilización , TactoRESUMEN
Facial reconstruction is a method that seeks to recreate a person's facial appearance from his/her skull. This technique can be the last resource used in a forensic investigation, when identification techniques such as DNA analysis, dental records, fingerprints and radiographic comparison cannot be used to identify a body or skeletal remains. To perform facial reconstruction, the data of facial soft tissue thickness are necessary. Scientific literature has described differences in the thickness of facial soft tissue between ethnic groups. There are different databases of soft tissue thickness published in the scientific literature. There are no literature records of facial reconstruction works carried out with data of soft tissues obtained from samples of Brazilian subjects. There are also no reports of digital forensic facial reconstruction performed in Brazil. There are two databases of soft tissue thickness published for the Brazilian population: one obtained from measurements performed in fresh cadavers (fresh cadavers' pattern), and another from measurements using magnetic resonance imaging (Magnetic Resonance pattern). This study aims to perform three different characterized digital forensic facial reconstructions (with hair, eyelashes and eyebrows) of a Brazilian subject (based on an international pattern and two Brazilian patterns for soft facial tissue thickness), and evaluate the digital forensic facial reconstructions comparing them to photos of the individual and other nine subjects. The DICOM data of the Computed Tomography (CT) donated by a volunteer were converted into stereolitography (STL) files and used for the creation of the digital facial reconstructions. Once the three reconstructions were performed, they were compared to photographs of the subject who had the face reconstructed and nine other subjects. Thirty examiners participated in this recognition process. The target subject was recognized by 26.67% of the examiners in the reconstruction performed with the Brazilian Magnetic Resonance Pattern, 23.33% in the reconstruction performed with the Brazilian Fresh Cadavers Pattern and 20.00% in the reconstruction performed with the International Pattern, in which the target-subject was the most recognized subject in the first two patterns. The rate of correct recognitions of the target subject indicate that the digital forensic facial reconstruction, conducted with parameters used in this study, may be a useful tool.
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Cara/anatomía & histología , Procesamiento de Imagen Asistido por Computador/métodos , Adulto , Brasil , Bases de Datos Factuales , Femenino , Antropología Forense , Humanos , Imagenología Tridimensional , Persona de Mediana Edad , Fotograbar , Programas Informáticos , Tomografía Computarizada por Rayos X , Interfaz Usuario-ComputadorRESUMEN
This study aimed to develop a plate to treat fractures of the mandibular body in dogs and to validate the project using finite elements and biomechanical essays. Mandible prototypes were produced with 10 oblique ventrorostral fractures (favorable) and 10 oblique ventrocaudal fractures (unfavorable). Three groups were established for each fracture type. Osteosynthesis with a pure titanium plate of double-arch geometry and blocked monocortical screws of free angulation were used. The mechanical resistance of the prototype with unfavorable fracture was lower than that of the favorable fracture. In both fractures, the deflection increased and the relative stiffness decreased proportionally to the diminishing screw number The finite element analysis validated this plate study, since the maximum tension concentration observed on the plate was lower than the resistance limit tension admitted by the titanium. In conclusion, the double-arch geometry plate fixed with blocked monocortical screws has sufficient resistance to stabilize oblique fractures, without compromising mandibular dental or neurovascular structures.