3D model construction and biomechanical analysis of temporomandibular joint disc perforation based on arthrography.

Objectives: Disc perforation (DP) is a severe type of temporomandibular joint (TMJ) disorder. Arthrography-assisted CBCT can visually detect the location and size of DPs. This study aims to use imaging modeling software to construct a three-dimensional (3D) visual model of DP, simulating its biomechanical impact on the TMJ to provide a scientific basis for diagnosis and treatment.

Materials and methods: TMJ imaging data were obtained through arthrography and CBCT scans. Imaging modeling software was used to reconstruct and measure the DICOM files in 3D. The model was imported into biomechanical analysis software to simulate the static occlusal state of the mandibular muscles on the TMJ. The effects of DP on the mechanical properties of the TMJ were assessed via von Mises stress and total deformation analysis.

Results: (1) The maximum von Mises stress (MVMS) on the affected side of the disc was significantly greater than that on the unaffected side. This stress was negatively correlated with the height of the condylar head and positively correlated with the perforation volume. (2) The maximum total deformation (MTD) of the affected side's disc was significantly greater and negatively correlated with the condylar head height. (3) The MVMS of the condyle was markedly greater on the affected side than on the unaffected side.

Conclusion: (1) DPs may increase stress on bilateral TMJs, with the affected side experiencing significantly greater stress. (2) A larger perforation volume can result in greater stress on the affected side's disc. (3) The height of the affected condylar head can have an adverse effect on the stress and deformation of bilateral TMJs.

Clinical relevance: TMJ arthrography can assist clinicians in accurately determining the location, morphology, and size of the disc perforation, enabling early diagnosis and intervention to prevent further enlargement. Additionally, the restoration and protection of the condylar head height contribute to maintaining the stability of the intra-articular stresses within the TMJ.