Ústav mechaniky těles, mechatroniky a biomechaniky
Browse
Recent Submissions
Now showing 1 - 5 of 84
- ItemInfluence of Dental Implant Insertion Depth on Strain in Periimplant Bone Tissue(Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, 2024-05-14) Thomková, Barbora; Borák, Libor; Podešva, Pavel; Podešva, Martin; Joukal, Marek; Marcián, PetrThis study investigates the influence of dental implant insertion depth on strain states within the peri-implant bone tissue. Using a finite element model based on a human mandible CT data, variations in insertion depth were simulated, ranging from 0 mm to 2 mm in 0.5 mm increments. The analysis focused on a defined volume around the implant, evaluating strain intensities categorized according to the Mechanostat hypothesis. Results revealed notable differences in strain distribution within cancellous bone with increasing insertion depth, highlighting potential implications for bone response. While cortical bone showed consistent strain patterns, variations in cancellous bone suggest a nuanced relationship between insertion depth and periimplant bone strain.
- ItemImpact of early cleft lip and palate surgery on maxillary growth in 5-and 10-Year-old patients with unilateral cleft lip and palate: a cross-sectional study(BMC, 2024-10-29) Nováková, Magda; Bryšová, Alena; Vokurková, Jitka; Marcián, Petr; Borák, Libor; Košková, OlgaObjectives This study evaluated maxillary growth and dental arch relationships at 5 and 10 years of age in patients with unilateral cleft lip and palate (UCLP) who underwent early cleft lip and palate surgery. Methods 28 patients with UCLP who underwent cleft lip surgery in neonatal age and cleft palate surgery at average age of 7 months without orthodontic treatment (intervention group) were measured for intercanine and intermolar distances and for dental arch length. These measurements were compared with those of 30 healthy participants in a control group. Dental arch relationships in the intervention group were evaluated by 5-YO index at 5 years and the GOSLON Yardstick score at 10 years of patients' age. Results Patients in the intervention group had significantly shorter mean intercanine distance and arch length than control patients at both 5 and 10 years of age (p<.001 for all). There were no significant differences in intermolar distance at both 5 (p = .945) and 10 years (p = .105) of patients' age. The average 5YO index increased from 2.46 to an average GOSLON 10-year score of 2.89 in intervention group. Conclusion Intercanine distance and dental arch length of patients with UCLP are significantly reduced at 5 and 10 years after early cleft lip and palate surgeries compared to the healthy population. Dental arch relationships at 5 and 10 years of patients with UCLP show comparable outcomes to those reported by other cleft centers.
- ItemApparent Young´s modulus of human cranial cancellous bone(Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, 2024-05-14) Votava, Tomáš; Marcián, Petr; Borák, Libor; Fuis, Vladimír; Zikmund, Tomáš; Kaiser, Jozef; Wolff, JanThis study investigates the biomechanical behavior of cancellous bone in the os occipitale through finite element modeling. Utilizing micro-computed tomography scans, 47 bone segments were analyzed, and their apparent Young's moduli of each segment were determined in three orthogonal directions. The results revealed strong directional dependencies of Young’s modulus on bone volume fractions. In contrast, nondirectional dependency exhibited a weaker correlation, indicating an orthotropic elasticity. The derived correlation equations offer an efficient means to describe cancellous bone in cranial biomechanical simulations, especially when a detailed trabecular representation is impractical.
- ItemImpact of different disinfection solutions on mechanical properties of orthodontic impress silicone material(Brno University of Technology, Czech Academy of Sciences, 2024-05-14) Hrubanová, Anna; Thomková, Barbora; Košková, Olga; Richtrova, Michaela; Borák, Libor; Stourac, Petr; Marcián, PetrThis study explores the influence of disinfection on silicone material used in cleft protection and orthodontic impressions. A series of uniaxial tensile tests were conducted to evaluate the mechanical properties after disinfection. Statistical analysis of stress-strain curves at various stress levels using one-way ANOVA showed no significant differences, supporting the hypothesis that disinfection does not compromise the material properties of the silicone used for the cleft protection with obturators. Additionally, the study explores the utilization of 3D printing for creating a casting mold used in the manufacturing of silicon-based products.
- ItemFracture predictions in impact three-point bending test of European beech(Springer Nature, 2024-08-31) Kubík, Petr; Šebek, František; Hassan Vand, Mojtaba; Brabec, Martin; Tippner, JanHardwood has become widespread in European forests. The strongest factor is climate change and damage to conifers by the bark beetle. The effort to study hardwoods grows with increasing volume of applications. Therefore, European beech wood was investigated under two impact loads in two material directions, resulting in four unique combinations supplemented by the measurement of the friction coefficient. Then, it was computationally simulated to reproduce the cracking, while the material model reflected the orthotropic behaviour in elasticity, plasticity and failure. The model was coded using the user subroutine in Abaqus to initiate and propagate the crack using the element deletion. The resulting reaction forces were in good agreement with those from the experiments. Cracking was numerically simulated in three of four cases as experimentally observed, however, upon larger deflections. Therefore, the model is applicable for further investigations.