The microscopic structure and function of the vascular retrodiscal pad of the human temporomandibular joint.

The highly vascular retrodiscal pad attaches the articular disc of the temporomandibular joint to osseous structures posterior to it. There is debate as to whether or not the pad includes erectile tissue. Histological examination of 11 retrodiscal pads revealed thick-walled muscular arteries, thin-walled veins and numerous vascular sinuses, which is different from the erectile tissue of the corpora cavernosa. Its histological features and position within the joint suggest that the retrodiscal pad may function differently from other human joints due to: (1) the large amount of distraction it undergoes relative to its size and (2) its location anterior to the ear.