Mechanisms of disc displacement in temporomandibular joint (TMJ) internal derangement (ID) in mandibular asymmetry have not been clearly defined. This study examines the degree and direction of disc displacement and their relationship with vertical asymmetry in terms of both clinical and biomechanical aspects. A retrospective study of disc displacement was performed in 31 mandibular asymmetry patients using MR imaging. The degree and direction of disc displacements on the shifted side and contralateral side TMJ were investigated with the degree of vertical asymmetry. Furthermore, three-dimensional finite element models of entire mandible include TMJ and maxillary teeth in occlusion were created to simulate displacement of the articular disc during clenching condition. The direction of displacement on the shifted side and contralateral side were significantly different. Articular disc has tendencies to displace more on the shifted side even in mild degree of vertical asymmetry. The degree of displacement was correlated with the amount of asymmetry. The MR results were consistent with the tendencies of disc displacement predicted from the finite element models. We suggest that disturbance in the direction of stress distribution through asymmetry of the mandible is one of the mechanisms related to disc displacement.
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BJR Case Rep
January 2025
Dubai Health, Dubai 1853, United Arab Emirates.
Sci Rep
January 2025
Khulna University of Engineering and Technology, Khulna, 9203, Bangladesh.
Magnetic resonance (MR) images are commonly used to diagnose prolapsed lumbar intervertebral disc (PLID). However, for a computer-aided diagnostic (CAD) system, distinguishing between pathological abnormalities of PLID in MR images is a challenging and intricate task. Here, we propose a comprehensive model for the automatic detection and cropping of regions of interest (ROI) from sagittal MR images using the YOLOv8 framework to solve this challenge.
View Article and Find Full Text PDFBr J Oral Maxillofac Surg
November 2024
Center for Craniofacial Regeneration, Department of Oral and Craniofacial Sciences, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address:
A state-of-the-art scaffold capable of efficiently reconstructing the temporomandibular joint (TMJ) disc after discectomy remains elusive. The major challenge has been to identify a degradable scaffold that remodels into TMJ disc-like tissue, and prevents increased joint pathology, among other significant complications. Tissue engineering research provides a foundation for promising approaches towards the creation of successful implants/scaffolds that aim to restore the disc.
View Article and Find Full Text PDFPLoS One
December 2024
Public Health School, Gansu University of Chinese Medicine, Lanzhou, China.
Background And Objective: The prevalence rate of LDH and its influencing factors in Gansu is unclear. This study aims to analyze the prevalence of LDH and influencing factors in Gansu.
Methods: A stratified multi-stage random sampling method was used to obtain representative samples of residents more than 18 years old from <1500m, 1500-3500m, and >3500m altitude sites in Gansu, China, in June 2022 to August 2022.
Acta Neurochir (Wien)
December 2024
Neck-shoulder and Lumbocrural Pain Devision 1, Sichuan Province Orthopedic Hospital, Chengdu, 610041, China.
Background: For L5/S1 extraforaminal disc herniation, how to efficiently expose the herniated nucleus pulposus and reduce facet joint damage remain to be explored.
Methods: Lumbar discectomy was performed using a full-endoscopic transsacral approach, in which sacral ala and extraforaminal ligament were partially resected to expose the L5/S1 intervertebral disc. Methylene blue was used for disc staining, and the herniated nucleus pulposus was excised through the annular tear.
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