The superior compartment of the TMJ primarily performs which movement?

• A. Rotation
• B. Elevation
• C. Depression
• D. Translation (gliding)

Answer: (D)

The main idea here is that the superior compartment is where the jaw undergoes gliding movement. The articular disc splits the TMJ into two spaces; in the upper space, the condyle–disc complex can slide forward and downward along the articular eminence. This translational (gliding) motion enables the jaw to open wider and move forward. By contrast, rotation happens mainly in the lower (inferior) compartment, which handles the hinge-like opening and closing of the mouth. So the superior compartment’s primary function is translation (gliding), not rotation or pure depression/elevation.