scholarly journals Digital Workflow in Maxillofacial Prosthodontics—An Update on Defect Data Acquisition, Editing and Design Using Open-Source and Commercial Available Software

2021 ◽  
Vol 11 (3) ◽  
pp. 973
Author(s):  
Corina Marilena Cristache ◽  
Ioana Tudor ◽  
Liliana Moraru ◽  
Gheorghe Cristache ◽  
Alessandro Lanza ◽  
...  

Background: A maxillofacial prosthesis, an alternative to surgery for the rehabilitation of patients with facial disabilities (congenital or acquired due to malignant disease or trauma), are meant to replace parts of the face or missing areas of bone and soft tissue and restore oral functions such as swallowing, speech and chewing, with the main goal being to improve the quality of life of the patients. The conventional procedures for maxillofacial prosthesis manufacturing involve several complex steps, are very traumatic for the patient and rely on the skills of the maxillofacial team. Computer-aided design and computer-aided manufacturing have opened a new approach to the fabrication of maxillofacial prostheses. Our review aimed to perform an update on the digital design of a maxillofacial prosthesis, emphasizing the available methods of data acquisition for the extraoral, intraoral and complex defects in the maxillofacial region and assessing the software used for data processing and part design. Methods: A search in the PubMed and Scopus databases was done using the predefined MeSH terms. Results: Partially and complete digital workflows were successfully applied for extraoral and intraoral prosthesis manufacturing. Conclusions: To date, the software and interface used to process and design maxillofacial prostheses are expensive, not typical for this purpose and accessible only to very skilled dental professionals or to computer-aided design (CAD) engineers. As the demand for a digital approach to maxillofacial rehabilitation increases, more support from the software designer or manufacturer will be necessary to create user-friendly and accessible modules similar to those used in dental laboratories.

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1401
Author(s):  
Doo-Bin Song ◽  
Man-So Han ◽  
Si-Chul Kim ◽  
Junyong Ahn ◽  
Yong-Woon Im ◽  
...  

This study investigated the fitting accuracy of titanium alloy fixed dental prostheses (FDP) after sequential CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) fabrication. A three-unit FDP model connecting mandibular second premolars and molars was prepared and scanned to fabricate titanium FDPs by CAD/CAM milling. A total of six FDPs were sequentially milled in one titanium alloy disk using a new set of burs every time (n = 4). The fitting accuracy of FDPs was mesiodistally evaluated by a silicone replica technique and the measurement was triplicated at four different locations: MO (marginal opening), MG (marginal gap), AG (axial gap), and OG (occlusal gap). Data were statistically analyzed using ANOVA and Tukey’s HSD test. The fitting accuracy of PMMA (polymethyl methacrylate) FDPs milled using the worn or new bur were evaluated by the same procedure (n = 6). The mean dimensions of titanium FDP for all measuring positions, except for AG, were significantly increased from the third milling. However, no difference was noted between the first FDP and the second FDP milled with the same set of burs. Severe edge chippings were observed in all milling burs. Detrimental effects of the worn burs on the fitting accuracy were demonstrated in the CAD/CAM-milled PMMA FDP. The results recommend proper changing frequency of cutting burs to achieve the quality of fit and predictable outcomes for dental CAD/CAM prostheses.


Perception ◽  
1991 ◽  
Vol 20 (6) ◽  
pp. 755-769 ◽  
Author(s):  
Vicki Bruce ◽  
Patrick Healey ◽  
Mike Burton ◽  
Tony Doyle ◽  
Anne Coombes ◽  
...  

The extent to which faces depicted as surfaces devoid of pigmentation and with minimal texture cues (‘head models’) could be matched with photographs (when unfamiliar) and identified (when familiar) was examined in three experiments. The head models were obtained by scanning the three-dimensional surface of the face with a laser, and by displaying the surface measured in this way by using standard computer-aided design techniques. Performance in all tasks was above chance but far from ceiling. Experiment 1 showed that matching of unfamiliar head models with photographs was affected by the resolution with which the surface was displayed, suggesting that subjects based their decisions, at least in part, on three-dimensional surface structure. Matching accuracy was also affected by other factors to do with the viewpoints shown in the head models and test photographs, and the type of lighting used to portray the head model. In experiment 2 further evidence for the importance of the nature of the illumination used was obtained, and it was found that the addition of a hairstyle (not that of the target face) did not facilitate matching. In experiment 3 identification of the head models by colleagues of the people shown was compared with identification of photographs where the hair was concealed and eyes were closed. Head models were identified less well than these photographs, suggesting that the difficulties in their recognition are not solely due to the lack of hair. Women's heads were disproportionately difficult to recognise from the head models. The results are discussed in terms of their implications for the use of such three-dimensional head models in forensic and surgical applications.


Author(s):  
Olufunmilola Atilola ◽  
Julie Linsey

AbstractMany tools are being developed to assist designers in retrieving analogies. One critical question these designers face is how these analogues should be represented in order to minimize design fixation and maximize idea generation. To address this question, an experiment is presented that compares various representations' influence on creativity and design fixation. This experiment presents an effective example (analogue) as computer-aided design (CAD), sketch, or photograph representations. We found that all representations induced fixation, and the degree of fixation did not vary significantly. We also found that CAD representations encourage engineering designers to identify and copy the key effective features of the example. CAD and photo representations also produced a higher quality of design concepts. Results from this experiment offer insights into how these various representations may be used in examples during idea generation; CAD representations appear to offer the greatest advantages during the idea generation process. The results from this experiment also indicate that analogical databases of effective design examples should include CAD and photolike images of the analogue rather than sketches.


1998 ◽  
Vol 120 (11) ◽  
pp. 66-71 ◽  
Author(s):  
Mar Halpern

This article examines the growing usefulness of computer-aided engineering (CAE) programs for the design of electronics packaging. CAE combined with expert interpretation, can help manufacturers quickly satisfy demand for increasingly small yet reliable products. Currently, three classes of software specifically support electronics packaging design: integrated computer-aided design (CAD) CAE software, general-purpose CAE software, and specialty CAE software solutions. The integrated CAE software emphasizes automatic creation and updating of finite-element-analysis (FEA) models based on CAD geometry. The effectiveness of this associativity between CAD and FEA depends on the product behavior to be evaluated and the quality of implementation. CAE simulation can calculate the maximum acceptable loads on pins, as well as the vibration characteristics of components. Solids-based CAD helps detect interference problems across components, as in these exploded views of a disc drive and a headset. While several general-purpose CAE suppliers permit engineers to build customized environments for automating model creation, specialty suppliers such as Pacific Numerix deliver the specific automated capabilities and connector libraries.


Author(s):  
Александр Афанасьев ◽  
Afanasyev Afanasyev ◽  
Сергей Бригаднов ◽  
Sergey Brigadnov

The actual task in the field of computer-aided design of machine-building objects is to increase the level of automation of structural-parametric analysis of design solutions due to the repetition of their use, reducing the number of design operations and ensuring the corresponding competencies of designers. Developed methods and algorithms should ensure the acquisition of the necessary competencies for the designer for successful project activities in the field of computer-aided design, increasing the effectiveness of training. The system of analysis of design solutions should improve the quality of design solutions implemented in CAD KOMPAS-3D. In this paper, an overview of methods, systems and tools for analyzing design solutions implemented in the CAD-3D environment. The main features of such systems are described, their main disadvantages are identified: the lack of functions for determining non-optimal sequences of design operations, the inability to automatically rebuild a three-dimensional model of a machine-building product on the basis of analysis of the design model tree. A complex system for the analysis of project solutions and the training of a designer was developed and implemented, based on methods, models and algorithms for analysis and adaptive learning. The results of a computational experiment are presented, on the basis of which it can be concluded that the use of developed software enhances the efficiency and quality of the designer's training in the processes of constructing three-dimensional solid-state machine-building products in CAD KOMPAS-3D.


Author(s):  
Yi Lin Wong ◽  
Kin Wai Michael Siu

This chapter discusses the difficulties of CAD assessment through examining and reviewing existing CAD examination questions in Hong Kong. Based on the review, limitations of the current assessment are highlighted. It is argued that the existing method is inconsistent with the problem solving nature of the software and is unable to assess students with high ability and advanced drawing skills. Recommendation and improvement directions are suggested in the chapter to optimize the quality of assessment. Other subjects which also involve assessment of computer skills and design may also benefit from the recommendations.


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