What structure lies beneath the TMJ articular surfaces?

What structure lies beneath the TMJ articular surfaces?

• A. TMJ disc
• B. Articular capsule
• C. Glenoid fossa
• D. Condyle

Answer: (A)

A fibrocartilaginous articular disc sits between the two articular surfaces of the TMJ, within the joint capsule. This disc lies between the temporal bone surface and the mandibular condyle, effectively beneath them during articulation and dividing the joint into the upper and lower compartments. Its presence lets the jaw glide and hinge smoothly while cushioning and distributing loads to protect the bony surfaces. The articular capsule surrounds the joint, the glenoid fossa is the bony socket on the temporal bone, and the condyle is the mandibular articulating surface—none of these sit between the articulating surfaces in the same way the disc does.

A fibrocartilaginous articular disc sits between the two articular surfaces of the TMJ, within the joint capsule. This disc lies between the temporal bone surface and the mandibular condyle, effectively beneath them during articulation and dividing the joint into the upper and lower compartments. Its presence lets the jaw glide and hinge smoothly while cushioning and distributing loads to protect the bony surfaces. The articular capsule surrounds the joint, the glenoid fossa is the bony socket on the temporal bone, and the condyle is the mandibular articulating surface—none of these sit between the articulating surfaces in the same way the disc does.