The effects of temporomandibular joint internal derangement and degenerative joint disease on tomographic and arthrotomographic images.

In a blind study, 243 arthrograms were interpreted as showing normal disk position, anterior disk displacement with reduction, or anterior disk displacement without reduction. The presence or absence of a perforation of the posterior attachment or disk was recorded. Later, tomograms of the same patient were interpreted. The presence or absence of evidence of temporomandibular degenerative joint disease (TMDJD) was recorded. The condyle-to-fossa relationship was characterized as retropositioned or not retropositioned. O the 106 cases with tomographic evidence of TMDJD, 100 (94%) had arthrographic evidence of internal derangement (p less than 0.0001), whereas 47% of the cases with internal derangement (211) had evidence of TMDJD. Perforations were seen in 29 (27%) of the cases with degenerative joint disease and in none (0%) of the cases without TMDJD (p less than 0.001). In cases without TMDJD, 90% of the cases with internal derangement revealed condylar retropositioning (p less than 0.0001). With tomographic evidence of TMDJD present, the relationship between condylar position and disk position was not significant.