Superficial vascularity of temporomandibular joint retrodiskal tissue: an element of the internal derangement process.

Superficial vascular changes in the retrodiskal tissue are an aspect of the remodeling process during progressive anterior displacement of the temporomandibular joint (TMJ) disk. The salient portion of the remodeled retrodiskal tissue (RRT) is contained in a 3 x 3 grid of arthroscopic fields in the superior joint space, plus the tympanic portion of the remodeled retrodiskal tissue. A four-level vascularity classification system gives a statistically significant association between superficial avascularity of the remodeled retrodiskal tissue and progressive stages of disk derangement. In particular, simultaneous avascularity in both the tympanic remodeled retrodiskal tissue and the central arthroscopic field occurs with severe disk displacement without reduction. Analyses are based on 16 microscopic studies, 25 magnetic resonance imaging and tomographic imaging studies, and 26 arthroscopic studies.