Introduction: Currently, the replacement of defects of the mandible should be carried out immediately when removing tumors, eliminating ankilotic diseases of the temporomandibular joints, in the rehabilitation of children with syndromes, where one of the symptom complexes are defects in the face bones. At the same time, growth zones are disturbed, secondary deformations of the bones of the facial skeleton occur, occlusion changes, and an imbalance of the dentofacial system occurs. Modern technologies allow the computer simulation of the replacement of defects, the creation of graft models with visual prosthetics, the creation of a model of a complex construction of a future graft with areas of the receiving bed and fixation elements.
Objectives of the study: improvement of treatment of children with defects and deformities of the mandible through the introduction of methyl methacrylate and hydroxyapatite-based endoprostheses reinforced with hydrocarbon threads. Objectives of the study:
- Under laboratory conditions, investigate by the method of differential scanning calorimetry the influence of each of the components of the developed material on its polymerization process.
- Assess the effect of the nature and amount of hydrocarbon fiber on bending strength and impact strength of the material.
- To analyze the immediate and long-term results of bone grafting of the lower jaw in children with endoprostheses made of a composite material based on PMMA-HAP reinforced with carbon fibers.
In the study of isometric calorimetry and the influence of each of the components on the polymerization process, it has been established that, with the addition of HAP, the polymerization is accelerated. Adding modified HAP with polyacrylic acid slows down the reaction. With the introduction of polymethyl methacrylate - HAP dispersed carbon fiber, the polymerization process is inhibited sharply, which negatively affects the properties of endoprostheses, and therefore continuous hydrocarbon fibers are used for reinforcement.
At the second stage, the analysis of clinical material was carried out. In a retrospective study of clinical material, patients are divided into two groups.
The first group consisted of patients whose bone grafting was performed with PolyGap endoprostheses. In total, 90 children aged from 3 to 18 years old were operated on, 130 Polygap endoprostheses were used. In 18 cases, complications were observed during operation in the form of fractures, especially in the area of the condylar process.
The second group included patients who underwent bone grafting with hydrocarbon-reinforced endoprostheses. In this group, 60 patients were observed in whom bone grafting was performed with 82 endoprostheses reinforced with hydrocarbon threads. At the same time, complications were noted: in the form of exposing the endoprosthesis with its subsequent removal (in 6 patients), in the form of a fracture in 2 patients (condylar processes at a recidivism of TMJ ankylosis).
In the future, the methods of planning and manufacturing individual endoprostheses are improved using 3D modeling. A retrospective analysis of observation and physico-chemical studies based on methyl methacrylate and hydroxyapatite reinforced with hydrocarbon filaments showed that there were no complications in the form of fractures and mechanical damage to endoprostheses, which characterizes this type of material with enhanced strength characteristics and can later be successfully used in replacing jaw defects in children, as a stage of bone grafting, and as a permanent endoprosthesis according to indications.
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