Electronic thermography in the assessment of internal derangement of the temporomandibular joint. A pilot study.

Current diagnostic imaging methods to evaluate internal derangement of the temporomandibular joint (TMJ) include arthrotomography, arthroscopy, computed tomography, and magnetic resonance imaging. Most of these techniques either require ionizing radiation or are invasive, and all are expensive. Electronic thermography (ET) is an alternative diagnostic imaging modality that is inexpensive, nonionizing, and noninvasive. The purpose of this pilot study was to assess ET in the diagnosis of internal derangements of the TMJ. The study population consisted of 11 patients with internal derangement, and 12 normal patients. ET was conducted with an infrared thermographic unit, at 1.0 degrees and 0.5 degrees C sensitivity. Results from subjective blinded interpretations by two experts for the diagnosis of internal derangement of the TMJ were as follows: sensitivity, 86% (+/- 7.8%); specificity, 78% (+/- 7.1%). Results from objective measurements of thermal symmetry of the TMJ region were as follows: normal subjects, 89.3% (+/- 3.0%); internal derangement patients, 66.1% (+/- 16.2%); t21 = -4.89, p less than 0.01. In conclusion, ET appears to have some promise as a diagnostic aid in the evaluation of internal derangement of the TMJ. Additional, more extensive studies are needed before thermographic diagnosis of internal derangement is accepted clinically.