Search

Objective: To investigate characteristics of temporomandibular joint (TMJ) idiopathic condylar resorption (ICR) and analyze the related factors. Methods: A total of 755 consecutive patients (150 with ICR and 605 with anterior disc displacement [ADD]) from July 2015 to December 2018 were recruited. A comprehensive questionnaire characterizing the multidimensional impact of the TMJ was designed. Clinical examination and radiological evaluation were also performed. The odds ratio for each variable in the ICR group versus the ADD group was computed using logistic regression analysis. Results: Multivariate logistic regression analysis showed significant correlations between mouth opening restriction, disease course, mandibular retrusion, mandibular retrusion progression, skeletal Class II profile, and overjet in ICR patients. Conclusion: These results suggest that a longer ADD disease course might have a strong relationship with ICR. [ABSTRACT FROM AUTHOR]

This study addresses incomplete hydrogen emissions from hydrogen fuel cell exhausts, focusing on developing safe, efficient strategies to reduce residual hydrogen levels, ensuring compliance with strict environmental and safety norms. Despite maximizing hydrogen utilization, fuel cells inevitably emit residual hydrogen, posing safety risks. An innovative exhaust hydrogen eliminator design is proposed, examining the efficacy of a palladium/platinum catalyst in enhancing hydrogen removal via catalytic combustion. Through systematic investigation on a specialized test platform, factors like airflow, temperature, pressure, and hydrogen concentration influenced the catalytic hydrogen eliminator’s performance. Results highlight the palladium/platinum catalyst’s impact on hydrogen conversion, notably superior platinum performance over palladium, achieving maximum elimination rates of 61% and 96%, respectively. Catalyst shell temperature correlated with input hydrogen concentration, stabilizing near 102°C at 1.97% hydrogen, indicating stable catalytic reactions under tested conditions, pivotal for low-temperature combustion within the hydrogen eliminator.

Objective: During the development of temporomandibular joint osteoarthritis, endochondral ossification is compromised which leads to condylar degeneration; miR‐335‐5p in endochondral ossification in osteoarthritic condylar cartilage tissue remains unclear. Methods: Up‐regulated microRNA and its target gene were searched for endochondral ossification in osteoarthritis articular cartilage. The effect of increased or decreased miR‐335‐5p on endochondral ossification was evaluated by transfecting miR‐335‐5p mimics or miR‐335‐5p inhibitor in vitro in chondrocytes C28/I2. Finally, we injected the temporomandibular joint of rats intra‐articularly with agomiR‐335 in a unilateral anterior crossbite rat model to determine the in vivo regulation of miR‐335. Results: After the onset of temporomandibular joint osteoarthritis, miR‐335‐5p levels were gradually up‐regulated, whereas endochondral ossification‐related genes were down‐regulated in condylar cartilage specimens. Our results showed that miR‐335 inhibited endochondral ossification after administration of a miR‐335 antagonist into the temporomandibular joint articular cavity of a unilateral anterior crossbite rat model. AgomiR‐335, a miR‐335 agonist, inhibited matrix mineralization in fibrocartilage stem cells in vitro and then miR‐335‐5p negatively regulated chondrocyte activity by directly targeting SP1 via promoting transforming growth factor‐β/Smad signalling. Conclusion: miR‐335‐5p can significantly inhibit endochondral ossification; therefore, its inhibition may be beneficial for the treatment of temporomandibular joint osteoarthritis. [ABSTRACT FROM AUTHOR]

Objective: To investigate characteristics of temporomandibular joint (TMJ) idiopathic condylar resorption (ICR) and analyze the related factors., Methods: A total of 755 consecutive patients (150 with ICR and 605 with anterior disc displacement [ADD]) from July 2015 to December 2018 were recruited. A comprehensive questionnaire characterizing the multidimensional impact of the TMJ was designed. Clinical examination and radiological evaluation were also performed. The odds ratio for each variable in the ICR group versus the ADD group was computed using logistic regression analysis., Results: Multivariate logistic regression analysis showed significant correlations between mouth opening restriction, disease course, mandibular retrusion, mandibular retrusion progression, skeletal Class II profile, and overjet in ICR patients., Conclusion: These results suggest that a longer ADD disease course might have a strong relationship with ICR.

Introduction: Temporomandibular joint (TMJ) osteoarthritis (OA) is a common TMJ degenerative disease with an unclear mechanism. Synovial fluid (SF), an important component of TMJ, contains various proteins and metabolites that may directly contribute to OA. The present study aimed to investigate the influence of SF in TMJOA at the metabolite level., Methods: Untargeted and widely targeted metabolic profiling were employed to identify metabolic changes in SF of 90 patients with different TMJOA grades according to TMJ magnetic resonance imaging., Results: A total 1498 metabolites were detected. Most of the metabolites were amino acids and associated metabolites, benzene and substituted derivatives, and lipids. Among patients with mild, moderate and severe TMJOA, 164 gradually increasing and 176 gradually decreasing metabolites were identified, indicating that biosynthesis of cofactors, choline metabolism, mineral absorption and selenocompound metabolism are closely related to TMJOA grade. Combined metabolomics and clinical examination revealed 37 upregulated metabolites and 16 downregulated metabolites in patients with pain, of which 19 and 26 metabolites were positively and negatively correlated, respectively, with maximum interincisal opening. A model was constructed to diagnose TMJOA grade and nine biomarkers were identified. The identified metabolites are key to exploring the mechanism of TMJOA., Discussion: In the present study, a metabolic profile was constructed and assessed using a much larger number of human SF samples from patients with TMJOA, and a model was established to contribute to the diagnosis of TMJOA grade. The findings expand our knowledge of metabolites in human SF of TMJOA patients, and provide an important basis for further research on the pathogenesis and treatment of TMJOA., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhang, Zhang, Xia, Shen and Yang.)