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The Aim of the Study: Was to assess the impact of masticatory muscles hypertonicity on the bite formation., Materials and Methods: The study comprised 60 patients aged 7-14 years. Group 1 consisted of 20 individuals with Angle class 1 occlusion without masticatory muscle hypertonicity. Group 2 comprised 20 patients with class II malocclusion with hypertonicity of the masticatory muscles, group 3 - 20 patients class II malocclusion and no hypertonic masticatory muscles. All patients were examined according to common diagnostic protocol that included electromyography of the temporal and masticatory muscles at rest and in dynamics)., Results: In group 1 the mean IMPACT at rest was 242.8±133.6 µV, IMPACT during contraction was 880.50±201.5 µV; in group 2 - 797.9±413.0 and 1561.23±568.0 μV; in group 3 - 236.7±93.5 and 955.60±295.5 μV, correspondingly. The ratio of the activity of the temporal muscles to the masticatory muscles with neutral occlusion at rest correlates as 1:09, with compression 1:1. In patients with distal occlusion and the presence of hypertonicity at rest, the temporal muscles correspond to the chewing proper as 1:0.8, and with compression 1:09., Conclusion: The estimated ratio can contribute to the retroposition of the mandible, as well as inhibition of the growth of the mandible in the sagittal direction.

Objectives: The aim of this study was to compare the translucency levels of various composite materials that are positioned by their manufacturers as 'dentin,' 'opaque,' 'body,' and 'enamel' in relation to natural tooth tissues., Methods: Sixteen commercial composite materials and 10 natural tooth tissue samples (enamel and dentin) were studied. The differences in color of dried and hydrated samples were measured on a black-and-white background using CIELab coordinates. Analysis of variance (ANOVA) and Kruskal-Wallis tests were used to compare the translucency parameter (TP) values of the different materials (P < 0.05), and t test was used to compare the TP values for the dried and hydrated samples, with the significance set at P < 0.001., Results: The TP values of opaque shades for the studied composite materials ranged from 1.5 to 3.9, and those of enamel shades from 3.9 to 10.9. According to the obtained results, a body shade sample had a high level of translucency, comparable with some enamel shades of the materials studied (TP = 4.489 ± 0.505 after polymerization, and 3.916 ± 0.566 after 48 h of water storage). The translucency levels of dry composite samples and samples after hydration were not significantly different, while significant changes were observed for dentin and enamel (P < 0.05)., Significance: Choosing a composite material that is suitable for different clinical situations is a major challenge in everyday dental practice. Information about the relative translucency of various composites on the market and their compliance with natural tissues can help dentists to choose optimal restorative materials.