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Head and neck
Published in David A Lisle, Imaging for Students, 2012
The zygomatic bone forms the ‘cheekbone’ at the inferolateral orbital margin. This outwardly convex part of the zygoma is composed of thick, tough bone. Zygomatic fractures occur in four points of relative weakness (Fig. 11.1):Inferior orbital marginLateral wall of the maxillary sinusZygomatic archLateral wall of orbit (usually diastasis of the zygomaticofrontal suture).
Finite element analysis of human skull bone adaptation to mechanical loading
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Jose Gonzalez, Somer Nacy, George Youssef
A specific loading scenario was selected to elucidate the evolution of the skull’s bone densities through the modified bone remodeling approach in FEA. This loading scenario was based on the work of Moon et al. following clinical protocol Ant-MI-FM [+30] (Anterior Micro Implant Face Mask) (Moon et al. 2015), which places a load between the roots of the canine teeth and the first premolars, simulating the use of a spring within the maxillary that pushes it upward and forward. Therefore, the load was applied to nodes at molars, locations between roots of teeth, and at the mid-palate at a positive 30° from the occlusal plane, and a magnitude of 1000 grams (Moon et al. 2015). The foramen magnum was also fixed and acted as the primary support of the model. In the previous work in (MacGinnis et al. 2014; Moon et al. 2015), a simulation artifact was observed in the form of unintended rigid body rotation of the frontal bone due to resulting moments based on the remoteness of the fixation location of the foramen magnum from the loading point proximal to the occlusal line. While other researchers rectify this artificial rotational displacement issue by truncating the skull at the zygomatic bone, we opted to fix the frontal bone to prevent the rotational and get more insights into the spatial mechanical response.
Customized design and 3D printing of face seal for an N95 filtering facepiece respirator
Published in Journal of Occupational and Environmental Hygiene, 2018
Mang Cai, Hui Li, Shengnan Shen, Yu Wang, Quan Yang
Since the neutral expression is the most common expression in daily life, wearing performance under a neutral expression was of great interest to us. For all three subjects, the nasal bridge (location A) and the top of cheek (location B) exhibited high contact pressures under the neutral expression both while using the face seal and without it (Figures 9a, 10a, and 11a). This can be explained by the presence of bony prominences along the nasal bone and the zygomatic bone, which can lead to high contact pressures at the locations of the nasal bridge and top of cheek. However, by wearing the customized FFR face seal, the contact pressures under the neutral expression become smaller and more evenly distributed, which implies that wearing fit and comfort of FFR with the customized face seal improved significantly compared to the existing 3M 8210 N95 FFR. Therefore, this finding verified the feasibility of customizing the FFR face seal for the wearers.
Acute Pain, Neck Extensor Endurance, and Kinematic Changes Resulting from Sustained Neck Flexion during Smartphone Use
Published in IISE Transactions on Occupational Ergonomics and Human Factors, 2022
Kaitlin M. Gallagher, John Jefferson, Ashton Human, Caleb Burruss
A motion capture system (Qualisys AB, Gotenberg, Sweden) was used to assess head and trunk positions during the 30-minutes of smartphone use. Individual reflective markers (Figure 1) were placed bilaterally on the acromion, anterior superior iliac spine, zygomatic bone (cheek), and forehead. Two rigid marker clusters with five markers each were placed on a headband and the thorax. Marker data were sampled at 50 Hz. A static calibration trial was taken for the kinematic model while the participant sat in the banquet chair looking straight ahead. The individual markers were then removed. During data collection, the head and trunk positions were defined by their respective marker clusters (Figure 1).