Paralelização em GPU da segmentação vascular com extração de Centerlines por Height Ridges

The vascular segmentation is important in diagnosing vascular diseases like stroke and is hampered by noise in the image and very thin vessels that can pass unnoticed. One way to accomplish the segmentation is extracting the centerline of the vessel with height ridges, which uses the intensity as features for segmentation. This process can take from seconds to minutes, depending on the current technology employed. In order to accelerate the segmentation method proposed by Aylward [Aylward & Bullitt 2002] we have adapted it to run in parallel using CUDA architecture. The performance of the segmentation method running on GPU is compared to both the same method running on CPU and the original Aylward s method running also in CPU. The improvemente of the new method over the original one is twofold: the starting point for the segmentation process is not a single point in the blood vessel but a volume, thereby making it easier for the user to segment a region of interest, and; the overall gain method was 873 times faster running on GPU and 150 times more fast running on the CPU than the original CPU in Aylward

Avaliação da desadaptação das selas de próteses parciais removíveis após 1 a 5 anos de uso

The non-adaptation of the removable partial prosthesis (RPP) base to fibromucosal tissue is caused by resorption of residual ridges (RRR). The onset of bone resorption, which occurs after tooth extraction and continues throughout life, is accelerated by local or systemic factors. Aim: Assess the degree of non-adaptation of removable partial prosthesis saddles and the factors that influence it. Methodology: A sectional study was conducted with 81 patients using RPP who had their prostheses installed between 2003 and 2007 (1 to 5 years of use) at the Faculty of Dentistry of the Universidade Federal do Rio Grande do Norte (UFRN). After anamnese and clinical examination, a cast was made with polyether-based material, using the base of the prosthesis to make the impression. The base of the saddle was loaded with the casting material and positioned in the mouth, applying pressure on the supports. After polymerization, the material was removed from the saddle and measurements were taken at 3 different points using a pachymeter. Results: The non-adaptation of the saddle increased significantly with years of use (p = 0.005). The tooth-tissue supported prostheses obtained higher mean non-adaptation values than those of tooth supported prostheses (p < 0.001). Flaccid mucosa showed the worst non-adaptation results, which were statistically different from resilient mucosa (p < 0.001). The greater the extension of the saddle, the greater the non-adaptation (p < 0.001). The natural tooth antagonistic arch yielded better results than did RPP and total prosthesis (p < 0.001). Saddle non-adaptation at the free end was less near the pillar tooth and greater in the more posterior region (p < 0.001). When adaptation of the supports to the niches was poor, greater saddle non-adaptation occurred than when it was good or fair (p < 0.001). Saddles located in the posterior region of the arch had greater non-adaptation than those in the anterior region (p = 0.023). Conclusion: The mean non-adaptation of the saddle to the residual ridges was 0.27 mm. It can be concluded that, even with the use of RPP, bone height reduction was slight within the 1-5-year period of use. The following are factors that influence adaptation of the RPP saddle base: years of use, age, force transmission path to the alveolar bone, location of the toothless area, antagonistic arch, type of mucosa, adaptation of supports to the niche and extension of the saddle

Eficiência mastigatória e qualidade das próteses totais confeccionadas pelas técnicas tradicionais e simplificada: um ensaio clínico

Traditional methods for dentures fabrication require a wide clinical and laboratory procedures; however, there is no scientific evidence that these methods can produce better results when compared with simplified methods. Aim: To evaluate the effectiveness of a simplified methods for denture fabrication, comparing it to the traditional one through masticatory efficiency and prosthesis quality. Method: A randomized controlled trial was conducted with 50 patients, 25 rehabilitated with prosthesis produced by traditional technique and 25 rehabilitated by a simplified technique. The masticatory efficiency was evaluated by colorimetric method, using chewing capsules. The quality of prosthesis was obtained using a reliable and reproducible instrument. Statistical analysis of the masticatory efficiency and quality of the prosthesis was obtained by the Mann-Whitney test. Results: 39 patients completed the study, 18 on traditional group and 21 on simplified group. There was no difference between groups for the masticatory efficiency (p = 0.835) and the quality of the prosthesis (p = 0672). The evaluation of the overall quality of the prosthesis according to oral conditions, demonstrated significant difference on the height of the mandibular ridges (p = 0.010) and mandibular muscle attachments (p = 0.039). Conclusion: Complete dentures fabricated by simplified method were considered effective from the point of view of masticatory efficiency and quality of prosthetics, with results similar to those made by the traditional method.

Eficiência mastigatória e qualidade das próteses totais confeccionadas pelas técnicas tradicionais e simplificada: um ensaio clínico

Traditional methods for dentures fabrication require a wide clinical and laboratory procedures; however, there is no scientific evidence that these methods can produce better results when compared with simplified methods. Aim: To evaluate the effectiveness of a simplified methods for denture fabrication, comparing it to the traditional one through masticatory efficiency and prosthesis quality. Method: A randomized controlled trial was conducted with 50 patients, 25 rehabilitated with prosthesis produced by traditional technique and 25 rehabilitated by a simplified technique. The masticatory efficiency was evaluated by colorimetric method, using chewing capsules. The quality of prosthesis was obtained using a reliable and reproducible instrument. Statistical analysis of the masticatory efficiency and quality of the prosthesis was obtained by the Mann-Whitney test. Results: 39 patients completed the study, 18 on traditional group and 21 on simplified group. There was no difference between groups for the masticatory efficiency (p = 0.835) and the quality of the prosthesis (p = 0672). The evaluation of the overall quality of the prosthesis according to oral conditions, demonstrated significant difference on the height of the mandibular ridges (p = 0.010) and mandibular muscle attachments (p = 0.039). Conclusion: Complete dentures fabricated by simplified method were considered effective from the point of view of masticatory efficiency and quality of prosthetics, with results similar to those made by the traditional method.