Correlation between TMJ Space Alteration and Disc Displacement: A Retrospective CBCT and MRI Study

Area of Science:

• Dentistry
• Radiology
• Orthodontics

Background:

• Temporomandibular disorders (TMD) are common, with disc displacement being a significant factor.
• Accurate diagnosis of disc displacement is crucial for effective TMD management.
• Current diagnostic methods may have limitations in predicting disc displacement non-invasively.

Purpose of the Study:

• To evaluate the predictability of altered temporomandibular joint (TMJ) space ratios on cone beam computed tomography (CBCT) for diagnosing disc displacement.
• To determine if a large anterior and reduced posterior/superior joint space on CBCT is a reliable indicator of disc displacement.

Main Methods:

• Fifty-two symptomatic TMD joints (experimental) and 14 asymptomatic joints (control) were analyzed.
• Cone beam computed tomography (CBCT) was used to measure posterior-to-anterior (P-A) and superior-to-anterior (S-A) joint space ratios.
• Magnetic resonance imaging (MRI) confirmed disc position. Statistical analyses included ANCOVA and ROC analysis.

Main Results:

• Disc displacement was diagnosed in 45 of 52 experimental joints, while all 14 control joints had normal disc positions.
• Significantly different P-A and S-A ratios were observed between control, normal disc position (N), and disc displacement (DD) groups (p < 0.001).
• Altered P-A and/or S-A ratios on CBCT demonstrated high sensitivity and specificity for predicting disc displacement.

Conclusions:

• Altered joint space ratios, specifically a large anterior and reduced posterior/superior space, are highly predictive of temporomandibular joint disc displacement.
• CBCT assessment of joint space ratios offers a valuable, predictable diagnostic tool for disc displacement in TMD patients.
• This imaging biomarker can enhance diagnostic accuracy and inform treatment strategies for TMD.