EXPERIMENTAL AND THEORETICAL STUDIES OF THE HARDNESS OF ORTHODONTIC DEVICES USED IN THE TREATMENT OF DENTOGNATHIC DEFORMATIONS IN CHILDREN WITH CONGENITAL CLEFT LIP AND PALATE

Abstract

Congenital cleft lip and palate are the most common congenital malformations. Research on determining the principles of operation of orthodontic devices used in the treatment of children with cleft lip and palate allows justify the choice of the necessary design in each clinical case. The development and study of biomechanical models of deformable environments, assessment of the stressstrain state of biomechanical systems under force loads is necessary and relevant. Purpose. To conduct experimental and theoretical studies of the stiffness of four types of orthodontic devices used in orthodontic practice to stimulate the growth of the upper jaw and to verify the values of force reactions in the supports of orthodontic devices during their deformation. Materials and methods. Experimental and theoretical studies were conducted to determine the rigidity of orthodontic devices used in the treatment of children with congenital unilateral cleft lip and palate. Natural experiments to determine force reactions were carried out on the TIRAtest 2300 test rig. Results and Discussion. According to the results of experimental tests of samples of orthodontic devices, graphs of the dependence of the force amplitudes on the deformations created by the mechanism of the helical transmission of the movement of the device along the specified trajectory were constructed. The verification of experimental data for force reaction values was carried out for the geometric model of the type I orthodontic device depending on the axial movements of the kinematic mechanism rod. A simulated 3D model of a device sample was created based on digital scanning data in STL format of a live object. Conclusions. The design and technological parameters of the kinematic mechanism of orthodontic devices have been established. Verification of the distribution of force reactions of orthodontic devices during their deformation allows obtaining new data on the magnitude of external loads on the jawbones in the treatment of children with congenital cleft lip and palate, which can be as a methodical basis for rational orthodontic treatment.