Effect of TMJ disc position on condylar bone remodeling after arthroscopic disc repositioning surgery

Abstract

PurposeThe objective of this study was to analyze the effect of TMJ disc position on condylar bone remodeling after arthroscopic disc repositioning surgery. MethodsNine patients with anterior disc displacement without reduction (ADDWoR, 15 sides) who underwent arthroscopic disc repositioning surgery were included. Three-dimensional (3D) reconstruction of the articular disc and the condyle in the closed-mouth position was performed using cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) data. Then, the CBCT and MRI images were fused and displayed together by multimodal image registration techniques. Morphological changes in the articular disc and condyle, as well as changes in their spatial relationship, were studied by comparing preoperative and 3-month postoperative CBCT-MRI fused images. ResultsThe volume and superficial area of the articular disc, as well as the area of the articular disc surface in the subarticular cavity, were significantly increased compared to that before the surgical treatment（P < 0.01）. There was also a significant increase in the volume of the condyle (P < 0.001). All condyles showed bone remodeling after surgery that could be categorized as one of two types depending on the position of the articular disc, suggesting that the location of the articular disc was related to the new bone formation. ConclusionsThe morphology of the articular disc and condyle were significantly changed after arthroscopic disc repositioning surgery. The 3D changes in the position of the articular disc after surgery tended to have an effect on condylar bone remodeling and the location of new bone formation.