Accuracy of measures of temporomandibular joint space and condylar position with three tomographic imaging techniques

Fourteen temporomandibular joints in seven dry skulls, representing the distribution of horizontal and vertical condylar axis inclinations of a larger population, were imaged with three tomographic projection techniques. Closest anterior and posterior joint spaces were measured on radiographs, and sectioned plaster casts were made from impressions of actual joint space, Individualized horizontal and vertical correction of the condylar axis produced significantly more accurate (p less than 0.005) measures of condylar space than either standard 20-degree horizontal correction (SHC) or individualized horizontal correction (IHC) of the axis. Representations of joint space by SHC and IHC were not significantly different from each other. Numbers of uninterpretable images displayed a similar pattern of 9.5% for individualized horizontal and vertical correction, 14% for IHC, and 17% for SHC. This study supports the use of fully individualized condylar axis correction with temporomandibular joint tomography for increased accuracy of visualization of the osseous anatomy of the joint.