Accuracy of infrared thermography of the masticatory muscles for the diagnosis of myogenous temporomandibular disorder.

Objective: The purpose of this study was to evaluate the accuracy of infrared thermography of the central point of the masseter and anterior temporalis muscles for the diagnosis of myogenous temporomandibular disorder (TMD).

Methods: This is an observational study of university women with and without TMD. Through the use of the Research Diagnostic Criteria for Temporomandibular Disorders, 104 women were divided into a TMD group (n = 52) and control group (n = 52). All volunteers had their masseter and anterior temporalis muscles evaluated by infrared thermography. The receiver operating characteristic (ROC) curve was used to determine the accuracy of diagnosis (area under the ROC curve), the best cut-off point, sensitivity, and specificity.

Results: No significant differences were observed (P > .05) in the skin surface temperature of the masticatory muscles, when the groups were compared. With regard to the ROC curve, the area under the curve was lower than the recommended for all the muscles tested, ranging from 0.433 to 0.502.

Conclusion: The findings of this study suggest that infrared thermography of the masticatory muscles is not an accurate instrument for the myogenous TMD diagnosis.