The aim of the study was to compare two types of mandible reconstructive operations with scapula and fibula free flaps: procedures with 3-D models from thermoplastic materials and conventional planning surgeries. 8 patients were treated due to an advanced oral cavity squamous cell carcinoma. In four patients with a mandibular defect, a physical 3-D model consisting of the reconstructed and unaffected sites was prepared for a reconstruction protocol. The 3-D models were designed based to high resolution CT scans. Assessment of comparative functionality (stability of junction, mobility, mastication ability) and cosmetics was examined in both groups, following a 8 weeks healing period with better results in group with 3D model. 3-D models for mandible and donor bones allow to obtain better functionality of restored mandible in comparison to the traditional method also significantly decreases time of the operation and allows to achieve the desired shape and esthetic effect within the 1/3 of the lower face.

The paper presents results of research conducted on a batch of additively manufactured individualized openwork wrist–hand orthoses made of thermoplastics and designed automatically based on 3D-scanned geometry of a given patient. The aim of the work was to establish an automated design process and find a reliable set of parameters for rapid and affordable manufacturing of usable orthoses on popular 3D printers, with little or no supervision of the process. The paper presents motivations, methodology of automated design, plan of manufacturing and testing, the obtained results in terms of process stability, fit and assessment by patient and strength of the obtained orthoses. Almost 100 manufacturing processes of ready-to-use orthosis parts were carried out in a controlled environment and their results were analyzed thoroughly. The results are promising, as most of the obtained products fulfil the strength criteria, although not all of them meet the economic criteria. As a result, a recommended set of process parameters was determined. These parameters were included in a prototype of the automated design and in a production system developed by the authors.

No abstract

Numerous experimental studies, including experiments performed by the authors, have shown that the part orientation during layer deposition has a very strong influence on final strength of a product manufactured by additive Fused Deposition Technology. The paper presents the results of tensile, bending and impact strength tests performed on samples of various orientations, made out of ABS material using FDM technology. The results of these tests allowed discovering a unique phenomenon -with the changing orientation, not only the values of strength indexes change, but macroscopic material behavior under load as well. The transition between a "yield point" and "brittle" material usually happens in a certain range of orientation values, named a critical orientation by the authors. The paper indicates supposed ranges of critical orientation for various types of loads.

Inter-operational surgery supplies manufactured additively using the FDM (Fused Deposition Modelling) technology are required to be sterilized before use. After manufacturing, the part should be sterilized using one of commonly used processes, without losing its dimensions and shape. The paper presents studies on manufacturing and sterilizing samples made out of ABS material and influence of the sterilization process on the dimensional accuracy of these samples.

The paper focuses on a problem of evaluation of strength of products manufactured using Fused Deposition Modelling technology. The presented research was aimed at developing a method for computation of deformation and stresses in any product manufactured using FDM technology, with consideration of important, strength-affecting process parameters. Finite Element Method calculations were realized using digital CAD models of the products, obtained by simulation of FDM process in a virtual environment. These models represent the macrostructure of additively manufactured elements. Results of calculations for sample geometries were verified by experimental studies. The obtained results are mostly correct, changes in approach are needed to make the computations possible to be performed in shorter time and with better results.

The paper presents the design and manufacturing process of an individualized wrist orthosis. The patient's upper limb was 3D scanned and the orthosis was designed using a CAD system. Each part of the orthosis consists of two different materials that fulfill different functions. By using the double-head Fused Deposition Modelling machine it was possible to produce these parts in a single process without the need for additional assembly operations. The orthosis has been tested for mutual fit of parts, strength and comfort of use.

No abstract