Search Results (143)

Background: Temporomandibular disorders are a generic term referred to clinical conditions involving the jaw muscles and temporomandibular joint with multifactorial pattern and genetic background. The aim of this observational study was to investigate the correlation between craniomandibular disorders and the presence of occlusal alterations. A clinical evaluation of the occlusal and articular status of the patients was carried out, integrating the latter with the electromyographic recording the activity of the masseter and temporalis muscles. Methods: A clinical observational study on 20 adults assessed temporomandibular disorders using DC/TMD criteria, anamnesis, clinical exams, occlusal and electromyographic analyses. Occlusion was evaluated morphologically and functionally. Electromyography tested static/dynamic muscle activity. Data were statistically analyzed using t-tests and Pearson correlation (p < 0.05). Results: Electromyographic analysis revealed significant differences between subjects with and without visual correction, suggesting that visual input influences masticatory muscle activity. Correlations emerged between occlusal asymmetries and neuromuscular parameters. These findings highlight clinical implications for mandibular function, muscle symmetry, and the potential for therapeutic rebalancing through targeted interventions. Conclusions: The study demonstrates a significant correlation between visual–motor integration and masticatory muscle efficiency. It emphasizes lateralized neuromuscular activation’s influence on occlusal contact distribution. Moreover, it identifies mandibular torsion–endfeel inverse correlation as a potential diagnostic marker for craniomandibular dysfunctions via surface electromyography. Full article

Sign language recognition plays a crucial role in enabling communication for deaf individuals, yet current methods face limitations such as sensitivity to lighting conditions, occlusions, and lack of adaptability in diverse environments. This study presents a wearable multi-channel tactile sensing system based on smart textiles, designed to capture subtle wrist and finger motions for static sign language recognition. The system leverages triboelectric yarns sewn into gloves and sleeves to construct a skin-conformal tactile sensor array, capable of detecting biomechanical interactions through contact and deformation. Unlike vision-based approaches, the proposed sensor platform operates independently of environmental lighting or occlusions, offering reliable performance in diverse conditions. Experimental validation on American Sign Language letter gestures demonstrates that the proposed system achieves high signal clarity after customized filtering, leading to a classification accuracy of 94.66%. Experimental results show effective recognition of complex gestures, highlighting the system’s potential for broader applications in human-computer interaction. Full article

Background/Objectives: The aim of the present study is to evaluate the influence of the healing abutment height on secondary implant stability measured by resonance frequency analysis. In this prospective observational clinical study of 30 implants, the secondary stability of the implant was measured via resonance frequency analysis of the abutment during the osseointegration process. Methods: Two groups were compared: a <4 group (n = 15), with a space between the healing abutment and the antagonist of <4 mm, and a ≥4 group (n = 15), with a space of ≥4 mm. Results: Statistically significant differences (p < 0.05) in the implant stability values obtained at surgery (T0) and at the eighth week of osseointegration (T8) were observed between the two groups, with higher values for the <4 group. Pearson’s correlation analysis revealed a trend towards a significant relationship with the mean force (−0.6546) and a linear inverse relationship, so that by decreasing the distance between the abutment and the contact with the antagonist, the secondary implant stability values increased. A comparison of the mesial and distal peri-implant marginal bone levels at T0 and T8 did not reveal statistically significant differences (p > 0.05). A greater healing abutment height, placing it closer to the antagonist, increases and accelerates secondary stability, as measured by resonance frequency analysis. Conclusions: The results of the study support the recommendation of using high healing abutments, placing the abutment close to the opposing occlusal plane, according to biomechanical criteria. Full article

Aim: To evaluate whether maximum occlusal loading and periodontal status are different between teeth presenting deflective occlusal contacts and those without such contacts, specifically adjacent and homologous teeth. Method: A cross-sectional study was conducted using OccluSense to detect deflective contacts and quantify occlusal load per tooth. For group comparisons, the Kruskal–Wallis, Friedman, Cochran’s Q, and chi-squared tests were used. Results: A total of 493 teeth with deflective contacts were compared to 473 adjacent (first control group) and 457 homologous teeth (second control group). Teeth with deflective contacts showed significantly higher occlusal loading (mean value: 208) than adjacent (72) and homologous teeth (97) (p < 0.05). They also exhibited more advanced periodontal damage, including deeper probing depths, greater gingival recession, alveolar bone loss, and a wider periodontal ligament space. Deflective contacts in centric relation were more strongly linked to periodontal deterioration than those in protrusive or lateral mandibular movements, despite similar occlusal forces. Conclusions: Within this study’s limitations, deflective occlusal contacts are associated with increased occlusal forces and more severe periodontal damage, suggesting a biomechanical factor in periodontal disease progression. Full article

Background/Objectives: Temporomandibular disorders (TMDs) are a group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint (TMJ), masticatory muscles, and related anatomical structures. Although magnetic resonance imaging (MRI) is considered a noninvasive and highly informative imaging modality for assessing TMJ soft tissues, few studies have examined how TMJ structural features observed on MRI findings relate to oral function and craniofacial morphology in female patients with malocclusion. To investigate the associations among TMJ structural features, oral function, and craniofacial morphology in female patients with malocclusion, using MRI findings interpreted in conjunction with a preliminary assessment based on selected components of the DC/TMDs Axis I protocol. Methods: A total of 120 female patients (mean age: 27.3 ± 10.9 years) underwent clinical examination based on DC/TMDs Axis I and MRI-based structural characterization of the TMJ. Based on the structural features identified by MRI, patients were classified into four groups for comparison: osteoarthritis (OA), bilateral disk displacement (BDD), unilateral disk displacement (UDD), and a group with Osseous Change/Disk Displacement negative (OC/DD (−)). Occlusal contact area, occlusal force, masticatory efficiency, tongue pressure, and lip pressure were measured. Lateral cephalometric analysis assessed skeletal and dental patterns. Results: OA group exhibited significantly reduced occlusal contact area (p < 0.0083, η² = 0.12) and occlusal force (p < 0.0083, η² = 0.14) compared to the OC/DD (−) group. Cephalometric analysis revealed that both OA and BDD groups had significantly larger ANB angles (OA: 5.7°, BDD: 5.2°, OC/DD (−): 3.7°; p < 0.0083, η² = 0.21) and FMA angles (OA: 32.4°, BDD: 31.8°, OC/DD (−): 29.0°; p < 0.0083, η² = 0.17) compared to the OC/DD (−) group. No significant differences were observed in masticatory efficiency, tongue pressure, or lip pressure. Conclusions: TMJ structural abnormalities detected via MRI, especially osteoarthritis, are associated with diminished oral function and skeletal Class II and high-angle features in female patients with malocclusion. Although orthodontic treatment is not intended to manage TMDs, MRI-based structural characterization—when clinically appropriate—may aid in treatment planning by identifying underlying joint conditions. Full article

Cardiovascular diseases are responsible for a large number of severe disability cases and deaths worldwide. Strong research in this field has been extensively carried out, in particular for the associated complications, such as the occlusion of small-diameter (<6 mm) vessels. Accordingly, in the present research, two random copolyesters of poly(butylene 2,5-furandicarboxylate) (PBF) and poly(butylene isophthalate) (PBI), were successfully synthesized via two-step melt polycondensation and were thoroughly characterized from molecular, thermal, and mechanical perspectives. The copolymeric films displayed a peculiar thermal behavior, being easily processable in the form of films, although amorphous, with T_g close to room temperature. Their thermal stability was high in all cases, and from the mechanical point of view, the materials exhibited a high ultimate strength, together with values of elastic moduli tunable with the chemical composition. The long-term stability of these materials under physiological conditions was also demonstrated. Cytotoxicity was assessed using a direct contact assay with human umbilical vein endothelial cells (HUVECs). In addition, hemocompatibility was tested by evaluating the adhesion of blood components (such as the adsorption of human platelets and fibrinogen). As a result, a proper chemical design and, in turn, both the solid-state and functional properties, are pivotal in regulating cell behavior and opening new frontiers in the tissue engineering of soft tissues, including vascular tissues. Full article

Quadruped robots have shown significant potential in disaster relief applications, where they have to navigate complex terrains for search and rescue or reconnaissance operations. However, their deployment is hindered by limited adaptability in highly uncertain environments, especially when relying solely on vision-based sensors like cameras or LiDAR, which are susceptible to occlusions, poor lighting, and environmental interference. To address these limitations, this paper proposes a novel sensor-enhanced hierarchical switching model predictive control (MPC) framework that integrates proprioceptive sensing with a bi-level hybrid dynamic model. Unlike existing methods that either rely on handcrafted controllers or deep learning-based control pipelines, our approach introduces three core innovations: (1) a situation-aware, bi-level hybrid dynamic modeling strategy that hierarchically combines single-body rigid dynamics with distributed multi-body dynamics for modeling agility and scalability; (2) a three-layer hybrid control framework, including a terrain-aware switching MPC layer, a distributed torque controller, and a fast PD control loop for enhanced robustness during contact transitions; and (3) a multi-IMU-based proprioceptive feedback mechanism for terrain classification and adaptive gait control under sensor-occluded or GPS-denied environments. Together, these components form a unified and computationally efficient control scheme that addresses practical challenges such as limited onboard processing, unstructured terrain, and environmental uncertainty. A series of experimental results demonstrate that the proposed method outperforms existing vision- and learning-based controllers in terms of stability, adaptability, and control efficiency during high-speed locomotion over irregular terrain. Full article

Efficient individual identification is essential for advancing precision broiler farming. In this study, we propose YOLO-IFSC, a high-precision and lightweight face recognition framework specifically designed for dense broiler farming environments. Building on the YOLOv11n architecture, the proposed model integrates four key modules to overcome the limitations of traditional methods and recent CNN-based approaches. The Inception-F module employs a dynamic multi-branch design to enhance multi-scale feature extraction, while the C2f-Faster module leverages partial convolution to reduce computational redundancy and parameter count. Furthermore, the SPPELANF module reinforces cross-layer spatial feature aggregation to alleviate the adverse effects of occlusion, and the CBAM module introduces a dual-domain attention mechanism to emphasize critical facial regions. Experimental evaluations on a self-constructed dataset demonstrate that YOLO-IFSC achieves a mAP@0.5 of 91.5%, alongside a 40.8% reduction in parameters and a 24.2% reduction in FLOPs compared to the baseline, with a consistent real-time inference speed of 36.6 FPS. The proposed framework offers a cost-effective, non-contact alternative for broiler face recognition, significantly advancing individual tracking and welfare monitoring in precision farming. Full article

Background/Objectives: This study aimed to explore the functional implications of occlusal changes during clear aligner treatment (CAT) to (a) analyze occlusal changes throughout CAT and the extent of post-treatment occlusal recovery; (b) assess the relationship between post-treatment occlusion and masticatory performance; (c) investigate whether case complexity, facial biotype, and type of malocclusion influence occlusal adaptation and functional outcomes; and (d) evaluate the presence and progression of signs or symptoms of TMDs in patients undergoing CAT. Methods: This longitudinal cohort pilot study included 42 individuals who underwent CAT. Occlusion was evaluated at three timepoints: before treatment (T0), at treatment completion (T1), and three months after with night-only aligner use (T2). Masticatory performance was assessed using a two-colored chewing gum test analyzed through colorimetric software. TMD signs/symptoms were assessed using the Diagnostic Criteria for TMD [DC/TMD]. Statistical analysis used non-parametric tests. Results: A significant decrease in occlusal contact area was observed during active CAT [p = 0.016], which partially recovered at follow-up. Individuals with normal facial proportions (normodivergent) showed more anterior contacts at T1 compared to hyperdivergent individuals [p = 0.013]. Masticatory performance remained stable between T1 and T2 [p = 0.528]. A weak negative correlation was found between posterior contact number and performance score at T1 [r = −0.378, p < 0.05], suggesting that more contacts may be linked to better chewing. No TMD signs or symptoms were detected at any timepoint. Conclusions: Although CAT temporarily reduces occlusal contact area, it does not negatively impact chewing efficiency or trigger TMD symptoms. These findings support the functional safety of CAT when treatment is properly planned and monitored. Full article

Accurate and effective fruit tracking and counting are crucial for estimating tomato yield. In complex field environments, occlusion and overlap of tomato fruits and leaves often lead to inaccurate counting. To address these issues, this study proposed an improved lightweight YOLO11n network and an optimized region tracking-counting method, which estimates the quantity of tomatoes at different maturity stages. An improved lightweight YOLO11n network was employed for tomato detection and semantic segmentation, which was combined with the C3k2-F, Generalized Intersection over Union (GIoU), and Depthwise Separable Convolution (DSConv) modules. The improved lightweight YOLO11n model is adaptable to edge computing devices, enabling tomato yield estimation while maintaining high detection accuracy. An optimized region tracking-counting method was proposed, combining target tracking and region detection to count the detected fruits. The particle swarm optimization (PSO) algorithm was used to optimize the detection region, thus enhancing the counting accuracy. In terms of network lightweighting, compared to the original, the improved YOLO11n network significantly reduces the number of parameters and Giga Floating-point Operations Per Second (GFLOPs) by 0.22 M and 2.5 G, while achieving detection and segmentation accuracies of 91.3% and 90.5%, respectively. For fruit counting, the results showed that the proposed region tracking-counting method achieved a mean counting error (MCE) of 6.6%, representing a reduction of 5.0% and 2.1% compared to the Bytetrack and cross-line counting methods, respectively. Therefore, the proposed method provided an effective approach for non-contact, accurate, efficient, and real-time intelligent yield estimation for tomatoes. Full article

Manual geometric modeling of timber structures is time-intensive and error-prone, impeding efficient structural analysis. To overcome this limitation, this study develops an automated framework for the rapid generation of 3D geometric finite element (FE) models directly from LiDAR point clouds. The methodology first employs a region-growing algorithm for component segmentation. This is followed by the integration of geometric feature extraction techniques to robustly determine the position, orientation, boundaries, and dimensions of structural elements. The extracted geometric information is then output as an executable APDL (ANSYS Parametric Design Language) file for parametric geometric modeling, incorporating interfaces for customizing material and connection properties. The proposed framework accurately reconstructs geometries with high fidelity. It effectively addresses challenges arising from occlusions and incomplete point cloud data through boundary inference and contact relationship analysis. This approach demonstrates substantial promise for applications in both heritage conservation and modern timber engineering. Full article

Objectives: The aim of this study was to compare the hardness, chemical composition, and microstructure of various self-ligating ceramic orthodontic brackets and enamel. Methods: Sixty ceramic brackets (0.022″ × 0.028″) from six different orthodontic firms (Damon^® Clear 2, Genius^® Crystal, Empower^® 2 Clear, Clarity^® Ultra, Alpine SL^® Clear, and Experience Ceramic^®) were tested using a microhardness tester and a scanning electron microscope (SEM) equipped with energy-dispersive spectroscopy (EDS). Results: The hardness of the ceramic brackets ranged from 1969.8 to 2567.3 VH. The statistical analysis using the Kruskal–Wallis and Mann–Whitney tests revealed significant differences in microhardness between most of the ceramic brackets. Additionally, this study found that passive self-ligating brackets exhibited a significantly higher hardness than that of active self-ligating brackets (p = 0.01). The SEM analysis showed that the variations in the oxygen and alumina composition between the six bracket types were also statistically significant (p = 0.01). Conclusions: Among all of the ceramic brackets tested, Alpine^® brackets displayed the lowest hardness values, making them a potential choice for minimizing enamel damage. Notably, the hardness of self-ligating ceramic brackets was found to be at least six times greater than that of enamel, raising concerns about their potential to cause trauma to the enamel of antagonistic teeth. Consequently, the researchers recommend avoiding bonding ceramic brackets to the mandibular teeth or elevating occlusion with turbo-bites to prevent traumatic contact during treatment. Full article

Gait recognition, as a non-contact biometric technology, offers unique advantages in scenarios requiring long-distance identification without active cooperation from subjects. However, existing gait recognition methods predominantly rely on single-modal data, which demonstrates insufficient feature expression capabilities when confronted with complex factors in real-world environments, including viewpoint variations, clothing differences, occlusion problems, and illumination changes. This paper addresses these challenges by introducing a multi-modal gait recognition network based on channel shuffle regulation and spatial-frequency joint learning, which integrates two complementary modalities (silhouette data and heatmap data) to construct a more comprehensive gait representation. The channel shuffle-based feature selective regulation module achieves cross-channel information interaction and feature enhancement through channel grouping and feature shuffling strategies. This module divides input features along the channel dimension into multiple subspaces, which undergo channel-aware and spatial-aware processing to capture dependency relationships across different dimensions. Subsequently, channel shuffling operations facilitate information exchange between different semantic groups, achieving adaptive enhancement and optimization of features with relatively low parameter overhead. The spatial-frequency joint learning module maps spatiotemporal features to the spectral domain through fast Fourier transform, effectively capturing inherent periodic patterns and long-range dependencies in gait sequences. The global receptive field advantage of frequency domain processing enables the model to transcend local spatiotemporal constraints and capture global motion patterns. Concurrently, the spatial domain processing branch balances the contributions of frequency and spatial domain information through an adaptive weighting mechanism, maintaining computational efficiency while enhancing features. Experimental results demonstrate that the proposed GaitCSF model achieves significant performance improvements on mainstream datasets including GREW, Gait3D, and SUSTech1k, breaking through the performance bottlenecks of traditional methods. The implications of this research are significant for improving the performance and robustness of gait recognition systems when implemented in practical application scenarios. Full article

Malocclusion can arise due to various causes and may impact not only temporomandibular joint (TMJ) disorders but also overall systemic health. This study aimed to evaluate the association of individual occlusal characteristics with sleep quality and stress levels in female college students. Occlusal analysis was conducted using T-Scan III on 84 participants (age: 21.7 ± 2.09), while sleep quality and stress levels were assessed using the Korean version of the Pittsburgh Sleep Quality Index and self-reported stress questionnaires, respectively. Sleep quality was categorized as “good sleeper” (≤5 points) or “poor sleeper” (>5 points). Stress levels were classified as Normal (≤13), Initial stress (14–16), Moderate stress (17–18), or Severe stress (≥19). The results indicated no significant differences in sleep quality based on occlusal characteristics. However, participants with Type A occlusion (posterior contact without anterior contact) exhibited higher stress scores than those with Type B occlusion. Correlation analysis showed a weak negative association between stress scores and occlusion type, but no significant relationship was found between occlusal characteristics, sleep quality, and stress levels. In conclusion, individual occlusal characteristics have limited explanatory power regarding their effects on sleep quality and stress. Full article

Background/Objectives: Jaw deformities affect not only facial aesthetics but also various oral functions. While previous studies have demonstrated that mandibular prognathism (MP) alters masticatory-induced brain blood flow (BBF), the temporal characteristics of these hemodynamic changes have remained unclear. In this cross-sectional observational study, we investigated the following two specific objectives: (1) whether food hardness affects not only the magnitude but also the temporal patterns of BBF changes during mastication and (2) how malocclusion is associated with these temporal hemodynamic responses. Methods: Twenty-six participants with normal occlusion (NORM) and twenty patients with MP participated in this study. BBF was measured using functional near-infrared spectroscopy, while participants chewed soft paraffin or hard gummy candy. Maximum oxygenated hemoglobin (oxy-Hb) values and time-to-peak BBF were analyzed. Results: While food hardness did not significantly affect maximum oxy-Hb within groups, the MP group showed significantly lower responses during hard gummy candy mastication compared to the NORM group. The occlusal contact area exhibited significant positive correlation with maximum oxy-Hb values, while the ANB angle, an indicator of intermaxillary skeletal relationship, showed no significant correlation with BBF parameters. The hard gummy candy/paraffin ratio of maximum oxy-Hb was significantly higher in the NORM group compared to the MP group. Time-to-peak BBF was approximately twice as long for hard gummy candy compared to paraffin in both groups, with no significant differences between groups. Conclusions: These findings reveal that while MP attenuates the magnitude of masticatory-induced BBF, particularly during hard food mastication, the temporal adaptation to increased food hardness is preserved. This dissociation between magnitude and timing effects suggests that intact basic neurovascular coupling mechanisms would be maintained even in the condition of altered masticatory function in a MP subject, which is providing new insights for rehabilitation strategies in orthognathic surgery cases. Full article