Deformation properties of mastoid area skin

Abstract

The mechanical properties of the skin have been studied in vivo and in vitro using various test methods. It has been found that with age, the skin undergoes considerably less deformation at the same voltage, which is probably due to the change of collagen and elastin nets. Two-dimensional biomechanical behavior and the content of collagen in human skin samples from different areas of topical localization were studied. The minimum and maximum reduction axes were determined after removal and their connection with Langer’s lines. The experimental equipment was designed to keep the geometry and measure loads acting perpendicular to the circle of skin samples. Using in vivo geometry of samples as a base, various deformations were applied. After the voltage relaxation, the final values of the voltage were taken and compared with the deformations. It was found that the axes of maximum and minimum stress do not coin-cide with the Langer’s lines, and rotated 10°. This article describes the structure of the mastoid area skin. After the objective morphological studies, we came to the conclusion that during the surgery on the mastoid region, namely cosmetic otoplasty and lower rhytidectomy, the length of stretching skin-fat grafts must be taken into account. No visible lesions were found in their deformation in the range of 5-10 mm. This is the optimal minimum and maximum limit of biomechanical parameters in such interventions. Patho-logical changes primarily in the form of balloon degeneration were observed at the 15-20 mm flap tension, indicating a greater likelihood of necrosis in the postoperative period. Deformation of the skin-fat grafts of 25 mm leads to irreversible changes and hemodynamic disorders, thus flap stretching within these parameters is unacceptable. The aim of this study was to investigate the morphological features of skin-fatty grafts of mastoid area at various stages of deformation. In the experiment we used 30 skin-fatty grafts taken from the patients with roughness during cosmetic otoplasty. These pieces were elongated at 5, 10, 15, 20, 25 mm respectively; they were colored by hematoxylin-eosin as well as van Gieson stain