Reconsideration of the bilaminar zone in the retrodiskal area of the temporomandibular joint.

The fibrous connection of the diskal attachment to the condyle and to the surrounding structures, and of the retrodiskal area was investigated histologically. Sections, obtained from six temporomandibular joints with the condyle protruded, were mainly observed. Most of the collagen fibers that compose the posterior band were attached to the condylar poles and to those vicinities behind them, and no diskal attachment was found to the posterior aspect of the condyle. Elastin-rich fibers that originate from the petrotympanic fissure were attached to the disk at the medial end. These fibers had many branches that compose a part of the retrodiskal area and were very wavy in spite of the protruded position of the disk-condyle complex. No other fibers directly connected the disk with the posterior wall of the fossa. Therefore we concluded that there were no upper and the lower strata as termed by Rees.