This article describes calculations of Cauchy pressure p_C of the crystalline lattice of alloys (Pettifor criterion), the Pugh ratio (Pugh criterion), and the Poisson ratio (Frantsevich criterion) characterizing plasticity and brittleness of materials. Plasticity of alloys on the basis of titanium nickelide TiNi and brittleness of Ti₅₀Ni_{50 – x}Fe_x (x ≥ 10%) compounds are discussed using the criteria as well as the association of mechanical properties of alloys with the type of chemical bonds between atoms. The coefficient of correlation of TiNi and TiNi–TiFe between the Cauchy pressure p_C and the Pugh ratio B/G (c_ij) is 96.76% (p < 0.001), between p_C and B/G (A) is 85.46% (p < 0.05), and between p_C and μ is 98.87% (p < 0.001), which signifies a strong statistical correlation between the parameters.

A review of studies of the mechanical properties of human and animal heart tissues has been performed. On the basis of published data, a form of approximating function is found for the dependence of Young’s modulus of the ventricles of the human heart on the magnitude of the deformation. The average values of Young’s modulus and other elastic constants were calculated and compared with the known experimental values. The coefficients C₁ and C₂ of the two-parameter hyperelastic myocardial Mooney–Rivlin model are calculated.

Relevance. Plastic and reconstructive surgery of the missing outer ear is not always successful and may cause complications. Prosthetic reconstruction using silicone ectoprostheses (epitheses) is an alternative solution to this problem. Purpose – the study aimed to verify clinical and microbiological protocol of prosthetic rehabilitation of patients with a missing auricle using temporary silicone epitheses during implant osseointegration placed for the final magnet-bar retention system and assessment of the prosthetic reconstruction effe ctiveness.Materials and methods. The study compared and analyzed the quality of life and microbial colonization of the skin biotope in the main group patients – with temporary silicone auricle epithesis during extraoral implant osseointegration and in the control group without such prostheses. Quality of life was assessed before and after treatment using the automated questionnaires (WHOQOL-BREF and QL PAER) developed by us for mobile devices. We determined the quantitative and qualitative composition of the skin microbiota behind the ear in all patients with fixed silicone samples for seven days.Results. According to all domains of the "WHOQOL-BREF" and "QL PAER" questionnaires, an integral index of QLI (p < 0.05) was reliably higher after prosthesis fixation in the main group. Skin biotope colonization by strains of resident microorganisms in the region of Technovent silicone epithesis increased if B-460 glue was applied, and the water-soluble G609 glue did not have a similar effect.Conclusion. A digital protocol for the manufacture of a temporary silicone epithesis of the auricle for the period of extraoral implant osseointegration, with the fixation on a water-soluble glue, improves the quality of life of patients with anotia and minimizes microbial colonization of the biotope of t he skin behind the ear.