Association between preoperative TMJ arthroscopic and MRI findings and temporomandibular symptoms in patients with skeletal Class II deformities

The temporomandibular joint (TMJ) significantly influences the outcomes of orthognathic surgery, particularly in patients with skeletal class II deformities. These patients often exhibit symptoms such as joint noise, pain, and limited mouth opening. Although magnetic resonance imaging (MRI) is commonly used to evaluate TMJ disorders due to its effectiveness in assessing the position of the articular disc, it has limitations in detecting disc perforations. This study aimed to investigate the relationship between preoperative MRI findings and arthroscopic observations in patients with skeletal class II deformities, focusing on identifying disc perforations. We examined 94 TMJs in 47 patients scheduled for orthognathic surgery. Preoperative MRI was performed to assess disc position, and arthroscopic examination was conducted to confirm intra-articular abnormalities, including disc perforations. The correlation between MRI findings and arthroscopic observations was statistically analyzed. MRI results showed that 69.1% of joints had anterior disc displacement without reduction ( ADDwo/R). Arthroscopic examination revealed disc perforation in 33.3% of the joints. Statistical analysis demonstrated a significant correlation ( p = 0.0036) between MRI-detected ADDwo/R and disc perforation observed during arthroscopy. Specifically, 30.1% of joints with ADDwo/R were found to have disc perforation. Additionally, arthroscopy revealed synovial hyperemia in many cases, suggesting that synovial inflammation may precede disc perforation. These findings suggest that TMJ arthroscopy is valuable in the preoperative evaluation of patients with skeletal class II deformities, as it can reveal critical internal abnormalities that may be missed by MRI alone. The high frequency of disc perforation observed in these patients may contribute to the postoperative relapse commonly seen in skeletal class II cases. This study highlights the importance of comprehensive preoperative TMJ evaluation, including arthroscopy, to improve surgical outcomes.