Temporomandibular joint structural changes in patients with and without internal derangement based on 3D...

The aim of this study is to investigate the morphological differences in temporomandibular joint (TMJ) structures according to the disc displacement status using cone-beam computed tomography (CBCT)-based three-dimensional (3D) reconstructed models.

Overall, 100 TMJs from 50 adult patients were retrospectively analyzed using magnetic resonance imaging (MRI) and categorized into three groups: normal, anterior disc displacement with reduction (ADcR), and without reduction (ADsR). CBCT data were reconstructed into 3D models using the Mimics software (Materialise, Leuven, Belgium), and anatomical parameters, including articular eminence angle, axial condylar inclination, anteroposterior position of the condyle, and vertical position of the condyle, were measured and statistically compared.

The articular eminence angle was highest in normal (33.11 ± 9.26°) and lowest in ADsR (26.86 ± 8.90°), with a significant difference (p = 0.011). The axial condylar inclination and vertical position of the condyle significantly differed between the groups (p < 0.05). These parameters decreased in the following order: Normal, ADcR, and ADsR. No significant differences were observed in the anteroposterior condyle positions.

TMJ disc displacement is associated with measurable structural changes in joint morphology. CBCT-based 3D analysis of TMJ structures may serve as a useful adjunct method to MRI for the diagnosis and understanding of internal TMJ derangement.