Radiographic examination of the abnormal temporomandibular joint

Diagnosis of TMJ complaints is a complex and difficult task. To better define treatment procedures a firm diagnosis must be established. Radiographs are an aid in confirming diagnosis of TMJ abnormalities. This article has discussed six basic TMJ abnormalities and suggested the optimal radiographic technique for confirming each specific abnormality. Because transmission techniques can only confirm radiographic changes, emission techniques should be considered to evaluate TMJ pathologic activity in early disease prior to definitive bony change. The following can be concluded: 1. In specific TMJ abnormalities, specific emission or transmission radiographs are useful for confirmation. Early definition of all TMJ osseous activity is better defined by emission techniques; while chronic disturbances cause structure change, which is best seen in transmission techniques. 2. Superimposition, angular distortion, reproducibility, and definition of cartilaginous structures (for example, the meniscus) are limitations of transmission techniques. These limitations can be improved by tomography, cephalometric-corrected tomography, computer-assisted tomography, and arthrography of the TMJ. 3. In emission technology structural definition as seen in transmission techniques is lost, while visualization of bone reactivity as seen in early disease is gained.