Computer Application for Creating Maxillo-Facial Prostheses for Children
Computer Application for Creating Maxillo-Facial Prostheses for Children

Summary/Abstract: The Faculty of Medicine, with all its specializations, is a very challenging choice for the high school graduates. The admittance exam is difficult, but it is just the beginning because, after this stage, the young students in the 1st year of study find themselves in front of an even more difficult situation – the lectures and the practical stages have often a high and dense level of scientific information, hard to be understood and learned, and the academic requirements are much more demanding than those in high school. That is why the percentage of students who obtain poor results in the first session of examinations is usually increased and can lead to serious consequences, such as abandoning studies. This situation is a challenge for the students, who are not prepared for the new demands and the new learning style, as well as for the teachers, who are interested to facilitate as much as possible this transition period and to help the students to understand better the scientific notions and to learn with pleasure. In order to reach these objectives, the solution is to use new didactic methods and tools, like the PowerPoint presentations, the online resources and the interactive lectures, based on questions, answers and discussions. Another tool, whose potential is briefly investigated in the present paper, is the using of videos, eventually uploaded online, on YouTube. We developed such videos as didactic materials for the Medical Informatics and Biostatistics practical stages, in order to explain theoretical concepts (databases and statistics) and practical procedures (how to perform different operations in Access and Excel); the videos are based on live demonstrations, combined with oral explanations and static images and are uploaded in the academic network, being available at any moment for the students. A comparative study showed that the marks obtained at the practical exam by the students who use these resources are better than the marks obtained at the same exam by the students in the previous generations, who didn’t have access to them. Also we asked 60 students from the 1st year of study, Faculty of Dental Medicine, through a questionnaire, about their opinions regarding the utility and the attractiveness of this teaching resource, as well as its role in simplifying the learning process, and their answers were generally favourable. These preliminary results encourage us to continue with this project and to extend it, but also to evaluate it permanently, in order to detect its limits.Maxillofacial prosthetics in the case of growing children has experienced different approaches over time, taking into consideration the complexity and the relative unpredictability of the mandible's bone growth. At present, the quantification of the mandibular growth is done by using direct measurements of the 3D model generated by the computed tomography, together with the possibility of highlighting the different growth rates between genders. The surgeries are based on two approaches: the autogenous grafts collected from the rib, which have an unpredictable growth rate or, in more severe cases, the implantation of a total temporomandibular joint prosthesis. The last one mentioned requires numerous adjustments throughout the patient's life, because of the mandibular growth. The purpose of this paper is to present a complete temporomandibular joint prosthesis, provided with a capsule which contains a distractor mechanism that can be adjusted with minimal invasiveness at certain periods of time during the child's growth, without the need of complex surgery. Proximal, both the components of the mandibular part and the fossa follow the anatomical shape of the implantation surroundings and are provided with holes for monocortical screws fixation. The fossa component allow the replication to some extent of anatomical and functional route, crossed by the condylar head during the maximum mouth opening while the movement inside the distractor component is based on a rack-and-pinion assembly, commanded by the pinion rotation (screwing) which ensure a good access and adjustment of the mechanism from outside the body. This mechanism is encapsulated in a biocompatible material and attached through fixation to the upper surface of the mandibular base component, the surface which is generated by the condilectomy plane. Thus, this paper describes a method of conceiving, designing, building and manufacturing of such a total prosthesis with a distractor. The computer route begins with data acquisition, 3D model reconstruction from DICOM files generated by the computer-tomography scan, processing, editing, and filtering by "Remesh" operations, artifact removal and export to STL format of the anatomical model. The design process of prosthetic structures and the establishment for each one their own technological paths is made according to the chosen manufacturing technologies: 3D print, respectively CNC.

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