Helena Willhelm de Oliveira

Dimensional error of selective laser sintering, three-dimensional printing and PolyJet™ models in the reproduction of mandibular anatomy

BACKGROUND Selective laser sintering (SLS), three-dimensional printing (3DP) and PolyJet are rapid prototyping (RP) techniques to fabricate prototypes from virtual biomedical images. To be used in maxillofacial surgery, these models must accurately reproduce the craniofacial skeleton. PURPOSE To analyze the capacity of SLS, 3DP and PolyJet models to reproduce mandibular anatomy and their dimensional error. MATERIAL Dry mandible, helical CT images, SLS, 3DP and PolyJet prototypes, and digital electronic caliper. METHODS Helical CT images were acquired from a dry mandible (criterion standard) and manipulated with the InVesalius software. Prototypes were produced using SLS, 3DP and PolyJet techniques. Thirteen linear measurements of each prototype were made and compared with the dry mandible measurements. RESULTS The results showed a dimensional error of 1.79%, 3.14% and 2.14% for SLS, 3DP and PolyJet models, respectively. The models satisfactorily reproduced anatomic details and the SLS and PolyJet prototypes showed greater dimensional precision and reproduced mandibular anatomy more accurately than the 3DP model. CONCLUSIONS The SLS prototype had a greater dimensional accuracy than the PolyJet and 3DP models. The PolyJet technique reproduced anatomic details of the mandible more accurately.

Comparison among dental, skeletal and chronological development in HIV-positive children: a radiographic study

The goal of this study was to evaluate skeletal, dental and chronological development in an HIV-positive group of children, as compared with a control group, during a four-year period. Panoramic radiographs and hand and wrist radiographs of 60 children were taken. The children, of both sexes, aged 5 years and 2 months to 15 years and 5 months, were selected as follows: 30 HIV-positive volunteers who had acquired the disease vertically, and 30 volunteers who did not present the HIV infection or any other systemic disease. All radiographs were technically standardized and analyzed according to criteria established by Nolla (dental age), Greulich and Pyle (bone age), and Eklöf and Ringertz (bone age). The results were submitted to Students t-test at a 5% level of significance. Based on the comparison between the chronological age and the dental or the skeletal age, significant differences were observed between HIV-positive and HIV-negative children, both in 1999 and in 2003 (p < or = 0.05). Considering the results obtained with the methodology used, it was concluded that HIV-positive children of both sexes presented delayed bone development despite the administration of antiretroviral drugs, and that HIV-positive female children presented younger dental ages compared with their chronological ages in 1999 and in 2003; and HIV-positive males, in 1999.

Avaliacão radiográfica da idade óssea em criancas infectadas pelo HIV por via vertical

OBJETIVO: O presente trabalho teve por objetivo avaliar o desenvolvimento de criancas infectadas pelo virus da imunodeficiencia adquirida (HIV) por contaminacao vertical, comparando-se dois metodos determinantes da idade ossea. MATERIAIS E METODOS: Analisou-se uma amostra de 100 criancas, com idades variando de 4 anos e 2 meses a 11 anos e 9 meses, que realizaram radiografias de mao e punho tecnicamente padronizadas e que, posteriormente, foram analisadas segundo os criterios dos metodos de Greulich e Pyle (1959) e de Eklof e Ringertz (1967). RESULTADOS: Os resultados obtidos mostraram diferencas estatisticas entre os metodos de analise radiografica do desenvolvimento esqueletico utilizados, com destaque para a maior sensibilidade em relacao ao metodo de Eklof e Ringertz (p < 0,05). O grupo feminino apresentou diferencas estatisticamente significantes entre os casos controle e HIV+ (sete casos) quando avaliados por este metodo (p < 0,05). CONCLUSAO: Constatou-se, com a presente pesquisa, que houve a influencia do HIV sobre o desenvolvimento esqueletico neste grupo de pacientes.

IS 3D-CT REFORMATION USING FREE SOFTWARE APPLICABLE TO DIAGNOSIS OF BONE CHANGES IN MANDIBULAR CONDYLES?

Objectives: This study evaluated the agreement of computed tomography (CT) imaging using 3D reformations (3DR) with shaded surface display (SSD) and maximum intensity projection (MIP) in the diagnosis of bone changes in mandibular condyles of patients with rheumatoid arthritis (RA), and compared findings with multiplanar reformation (MPR) images, used as the criterion standard. Material and Methods: Axial CT images of 44 temporomandibular joints (TMJs) of 22 patients with RA were used. Images were recorded in DICOM format and assessed using free software (ImageJ). Each sample had its 3DR-SSD and 3DR-MIP results compared in pairs with the MPR results. Results: Slight agreement (k = 0.0374) was found in almost all comparisons. The level of agreement showed that 3DR-SSD and 3DR-MIP yielded a number of false-negative results that was statistically significant when compared with MPR. Conclusions: 3DR-SSD or 3DR-MIP should only be used as adjuvant techniques to MPR in the diagnosis of bone changes in mandibular condyles.

Towards designing for equity: active citizen participation in eHealth

Purpose – Reducing inequity in accessing healthcare among rural and remote populations remains a problem. Internationally, eHealth is now touted as a potential solution, with a range of diverse approaches and impacts. Yet, the equity gains of implementing eHealth are often not realized due to a lack of effective strategies for citizen participation. The purpose of this paper is to present the background to, and results of, a multidisciplinary eHealth assistance project in a remote region of the Brazilian Amazon, highlighting the importance of citizen participation within planning processes.Design/methodology/approach – The project was conducted in three phases – pre‐mission, mission, and post‐mission. Discussions were held between health teams and local community leaders, and were coordinated by government health organizations in partnership with the Amazon State University. A multidisciplinary team visited five remote communities in the Brazilian Amazon, where participants underwent clinical assessment u...

eHealth Projects of the Microgravity Centre

This Chapter aims to present the activities of the Telemedicine Laboratory of the Microgravity Centre/PUCRS (Brazil) and to discuss eHealth initiatives around the globe, emphasising the benefits of the use of telecommunication and computer technologies in remote and deprived areas, where specialised medical care is limited or non-existent. Based on the experience of this Lab in the areas of eResearch, eLearning and eHealth Assistance, a review of virtual tools used in academic activities and of telemedicine endeavours applied for the identification and treatment of a broad range of diseases worldwide is presented. Relevant eHealth terminology is also introduced to help the reader gain a better understanding of the concepts described in this text.

The science transfer series: telemedicine in education, research and assistance

T is considered to be the delivery of healthcare services, where distance is a critical factor, by all healthcare professionals using information and communication technologies for the exchange of valid information for diagnosis, treatment and prevention of diseases and injuries, research and evaluation, and for the continuing education of healthcare providers, all in the interest of advancing the health of individuals and their communities. The term ‘telemedicine’ first came into use in the 1970s, but it is not a new concept and initiatives that fit the aforementioned definition have been applied since the early 1900s. To a large extent, the development of telemedicine has followed the advent of new technologies. The beginning of the 20th century welcomed the widespread use of telephones, an invention that has been used for medical work since its creation. Physicians communicated medical information to ships at sea using radios in the 1920s. Commercial air travel also adopted radio-based telemedicine for passengers taken ill mid-flight. Telemedicine experienced a boom with the Space Race and development of satellite technologies, enabling healthcare to be delivered in remote locations without the presence of a doctor. In recent times there has been an exponential proliferation of telemedicine initiatives around the world, both in number and diversity. This is in large part due to the internet and mobile phones. Internationally, the World Health Organization’s health-for-all policy for the 21st century centers on telemedicine and health telematics. Due to these technological advances, health professionals in remote areas are able to access information relevant to patient disease, diagnosis and therapy via the Internet, enabling the improvement of health services in areas lacking in specialist opinion. PUCRS University, through the Telemedicine Laboratory of the Microgravity Center, at the School of Engineering, has been developing projects in this area, with the intention of filling the gaps in current provision of health services in Brazil, which lack efficient tools to solve problems and difficulties in the diffusion of specialist services. This Laboratory, coordinated by Prof. Helena Willhelm de Oliveira of the PUCRS School of Dentistry, aims to expand the frontiers of health services through the development of research projects, using new communication technologies. To accomplish this goal, the Telemedicine Laboratory develops inter-institutional and multidisciplinary projects which are divided into three subareas: education, research and assistance.