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Fractures of the maxillofacial region are prevalent in both developed and developing nations. Maxillofacial fractures primarily occur as a result of incidents such as car crashes, physical assaults, and attacks. Although using miniplates to treat maxillofacial fractures is a widely accepted practice, the challenge lies in selecting the appropriate miniplate size that is tailored to the specific dimensions of the fracture in each patient. The study aims to evaluate and determine the most suitable design between a 2-hole miniplate and a 4-hole miniplate for securing a fractured mandible, with the ultimate goal of creating a customized solution for each patient. A mandible model is chosen with a diagonal length of 82mm and created perpendicular fracture gaps measuring 1mm to 3mm on the left buccolingual section of the solid model. A 2-hole and a 4-hole miniplate are designed with different thicknesses (ranging from 1mm to 2mm) and gap distances (ranging from 6mm to 12mm). The miniplates were put together in a model of the mandible. To test their effectiveness, the combination of the mandible model and plates was subjected to various muscle forces, as well as the force of biting, using finite element analysis. At the mandible location, the four-hole miniplate implantation exhibits superior stabilization in comparison to the two-hole miniplate assembly. The miniplate's size and dimensions can be adjusted depending on the size of the fracture in the mandible, resulting in a patient-specific solution for the implantation of miniplate in the mandible.

The present study assesses the concentration, probabilistic risk, source classification, and dietary risk arising from heavy metal (HMs) pollution in agricultural soils affected by coal mining in eastern part of India. Analyses of soil and rice plant indicated significantly elevated levels of HMs beyond the permissible limit in the contaminated zones (zone 1: PbSoil: 108.24 ± 72.97, CuSoil: 57.26 ± 23.91, CdSoil: 8.44 ± 2.76, CrSoil: 180.05 ± 46.90, NiSoil: 70.79 ± 25.06 mg/kg; PbGrain: 0.96 ± 0.8, CuGrain: 8.6 ± 5.1, CdGrain: 0.65 ± 0.42, CrGrain: 4.78 ± 1.89, NiGrain: 11.74 ± 4.38 mg/kg. zone 2: PbSoil: 139.56 ± 69.46, CuSoil: 69.89 ± 19.86, CdSoil: 8.95 ± 2.57, CrSoil: 245.46 ± 70.66, NiSoil: 95.46 ± 22.89 mg/kg; PbGrain: 1.27 ± 0.84, CuGrain: 7.9 ± 4.57, CdGrain: 0.76 ± 0.43, CrGrain: 8.6 ± 1.58, NiGrain: 11.50 ± 2.46 mg/kg) compared to the uncontaminated zone (zone 3). Carcinogenic and non-carcinogenic health risks were computed based on the HMs concentration in the soil and rice grain, with Pb, Cr, and Ni identified as posing a high risk to human health. Monte Carlo simulation, the solubility-free ion activity model (FIAM), and severity adjusted margin of exposure (SAMOE) were employed to predict health risk. FIAM hazard quotient (HQ) values for Ni, Cr, Cd, and Pb were > 1, indicating a significant non-carcinogenic risk. SAMOE (risk thermometer) results for contaminated zones ranged from low to moderate risk (CrSAMOE: 0.05, and NiSAMOE: 0.03). Fuzzy-TOPSIS and variable importance plots (from random forest) showed that Ni and Cr were mostly responsible for the toxicity in the rice plant, respectively. A self-organizing map for source classification revealed common origin for the studied HMs with zone 2 exhibiting the highest contamination. The positive matrix factorization model for the source apportionment identified coal mining and transportation as the predominant sources of HMs. Spatial distribution analysis indicated higher contamination near mining sites as compared to distant sampling sites. Consequently, this study will aid environmental scientists and policymakers controlling HM pollution in agricultural soils near coal mines.

Loosening and breakage of lumbar pedicle screw are the most common complications affecting the spinal stability. The design factors of the pedicle screw that may affect the fixation strength under bending load are pitch length, major diameter, thread profiles and geometry.

A suitable scaffold architecture is always desirable to get a favorable tissue response for bone tissue engineering. In this regard, a fluid–structure interaction (FSI) analysis was carried out on different porous scaffolds to observe the in vitro mechanical responses due to fluid flow, followed by a submodeling method to obtain the cellular deformation and strain. Different types of scaffolds were designed based on different porosity and architecture. The cell was modeled with cytoplasm, nucleus, cell membrane, and cytoskeletons. The main objective of the study is to examine the variation of cellular responses due to different porosity and architecture of the scaffold. The results of this study highlight that permeability is higher in the case of gyroid structure and wall shear stress (WSS) is higher in the case of diamond structure. The permeability of all scaffolds increases with the increase of porosity. The opposite trend is shown in the case of WSS within scaffolds. The cell is showing higher deformation when it is placed on the front position of the scaffold toward the direction of fluid flow. This study will guide us in predicting an ideal scaffold for better cell growth.

Knee-thigh-hip complex (KTH) was simulated under automobile frontal impact with variation of energy and impactor mass to locate the high stress-strain zones within the model. Finite element model of KTH in seating posture was developed with computed tomography scan based material properties. Material properties (modulus of elasticity) of pelvis, left and right femur were 4072.8 MPa, 17,605 MPa and 16,099 MPa respectively. Impactor velocities of 4.58 m/s, 5.80 m/s and 7.10 m/s were considered for 250 J, 400 J and 600 J with 23.8 kg impactor mass and 3.24 m/s, 2.65 m/s for 250 J with 47.6 kg and 71.4 kg impactor mass respectively. Five zones were identified which showed maximum von-Mises stress and strain for all the three energy variations. High mass (71.4 kg) impactor with low velocity was safer than low mass (47.6 kg, 23.8 kg) with high velocity for the same 250 J impact energy. This model may be helpful during vehicle design for injury protection to the car occupant's lower extremity.

A new iridoid glucoside, 10-O-veratroyleranthemoside (1) was isolated from the roots of Wendlandia tinctoria. The structure was established by spectroscopic (including 2D NMR) and chemical methods.

While this study is on the clinical development of temporomandibular joint disorders and understanding various biomechanical approaches through finite element analysis as a panacea, the primary aim is to perform a literature review. Usage of the biomedical prosthesis, over the years, including the initial development and later modernization with image processing and computer simulations, are briefly discussed from 1800 to 2021. Manual data handling was used to select 503 journal papers, of which 116 were further studied in this review. This review explains the complete biomechanical structure of the temporomandibular joint (TMJ), as it disclosed possible reasons for the disorders and shortcomings in the medical treatments. In the Boundary Condition and Discussion sections, the paper discussed the boundary conditions and the results of various studies from 2000 to 2021. It also discussed 36 papers with temporomandibular joint replacement (TMJR) devices, providing important information on the stress–strain distributions in the implant and the mandible-fossa component. Both custom and stock devices are discussed with a finite element method (FEM) approach, with a proper evaluation of multiple software for individual studies. Finally, TMJR devices are considered helpful for treating TMJ disorders. The FEM approach should be considered a precise and valuable biomechanical simulation tool for modifying and improving next-generation prosthetic devices.

The lumbar inter-vertebral joint (L4-L5) performs a very important role in transferring load from the upper portion of the body to the lower part, especially during bending activities. Failure such as bone fracture, tissue damage, disc rupture, etc. occurs very often in this region. Stress distribution patterns are very useful for evaluation of such failure. A three-dimensional finite element model of lumbar vertebral joint (L4-L5) along with an intervertebral disc was created. The geometry was based on standard literature and compared physically. For meshing cortical bone, 8-noded shell elements were used and 10-noded tetrahedra were used for meshing cancellous bone and intervertebral disc. The finite element model contained different isotropic material properties for different regions. The finite element model contained 105,876 elements, connected through 136,974 nodes. Stress analyses were done for different loading conditions such as axial compression of 2,000 N, bending moments for flexion with magnitudes of 5, 10, 15 and 20 Nm and lifting weight in hand with varying magnitude (20-80% of the body weight) and inclination (15°-90°) of the body with the vertical axis (0° for vertical body and 90° for horizontal body). The results were compared with previous similar type of studies, carried out by different researchers. This finite element model may be useful in clinical application for fracture assessment and spinal instrumentation.

An experimental validation with the pelvic bone or human cadaver has always been considered as a gold standard to assess the accuracy of the finite element predictions. The present study provides an approach in mechanical testing of pelvic bone and human cadaver under side impact load for the purpose of validating the previously developed finite element models of pelvis-femur complex and pelvis-femur-soft tissue complex, respectively. An experimental setup was designed and developed, instrumented with miniature piezoelectric load cell and miniature charge amplifier. PC based data acquisition system was used to record the impact force-time data. The support conditions of the experiments were applied on the finite element model and simulated under similar impact load. Considering all the load cases with pelvic bone and human cadaver, high correlation (r² = 0.966) and significance level (p < 0.0001) were obtained between the experimental and finite element results. It strongly suggests that the numerical results calculated by the finite element models could be used as a valid predictor of the actual results.

Pelvic injuries and fractures, caused by intrusion of car door structure due to car side impacts, are a serious problem worldwide. A 'car door padding', modelled with expanded polystyrene foam (EPS), is suggested in this study. This padding, formed with five layers of foams with different stiffness, is to be incorporated between the car door interior and outer body surface, around greater trochanter location of the occupant for protection from pelvic fracture (pubic rami fracture). To simplify the situation, in this finite element study the padding was fitted with a rigid impactor to hit the previously developed finite element model of the pelvis-femur-soft tissue complex with simplified representation of the whole body in occupant posture. It was observed that this padding has the capacity to reduce the risk of pubic rami fracture in case of car side impact for the occupants with the attenuation of peak impact force by 63% and a considerable reduction in peak strain by 91%. For the five-layered padding, the non-linear stiffness variations of EPS ('high to low' or 'low to high' across the pad thickness) also have an effect on the peak impact force, though less pronounced and it can be concluded that 'low to high' combination is preferred over 'high to low' combination.

The bone conditions of mandibular bone vary from patient to patient, and as a result, a patient-specific dental implant needs to be designed. The basal dental implant is implanted in the cortical region of the bone since the top surface of the bone narrows down because of aging. Taguchi designs of experiments technique are used in which 25 optimum solid models of basal dental implants are modeled with variable geometrical parameters, viz. thread length, diameter, and pitch. In the solid models the implants are placed in the cortical part of the 3D models of cadaveric mandibles, that are prepared from CT data using image processing software. Patient-specific bone conditions are varied according to the strong, weak, and normal basal bone. A compressive force of 200 N is applied on the top surface of these implants and using finite element analysis software, the microstrain on the peri-implant bone ranges from 1000 to 4000 depending on the various bone conditions. According to the finite element data, it can be concluded that weak bone microstrain is comparatively high compared with normal and strong bone conditions. A surrogate artificial neural network model is prepared from the finite element analysis data. Surrogate model assisted genetic algorithm is used to find the optimum patient-specific basal dental implant for a better osseointegration-friendly mechanical environment.

This study aims to understand the biomechanical effect of pedicle-screw fixation with different implant materials on lumbar spine. FE method is used to develop three-dimensional model of lumbar spine (L1-S). Three level pedicle-screw-rod is attached to the model with two different rods: Stainless Steel (SS) and poly-ether-ether-ketone (PEEK). The implanted models along with intact models are simulated for different physiological conditions such as axial rotation, lateral bending and flexion-extension under +- 6, 8 and 10 Nm moment with 500 N compressive loads. The spinal biomechanics found sensitive to the elastic modulus of the rod material. In case of pedicle screw fixation with SS, the ROM is very less (1.3deg for extension and 2.88deg for flexion) as compared to natural model. For PEEK rod, ROM is increased 3 to 4 times for axial rotation, 4 to 7 times for lateral bending and 1.8 to 2 times for flexion-extension. SS rods share more load and generate less stress on vertebrae compared and PEEK rods. For pedicle screw fixation, the foramen height does not vary significantly with variation of load and rod materials. SS rods resist the ROM on the implanted region affecting the kinematics of the spine undesirably. The ROM may be improved to some extent by using lower stiffness rod materials like PEEK. However pedicle screw fixation device prevents reducing inter-vertebral foramen height and foramen area, without affected by material stiffness.

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