The diagnostic value of pressure algometry for temporomandibular disorders.

The aim of this study is to determine the diagnostic value of pressure algometry in temporomandibular disorders. Two hundred volunteers aged 19.3 to 27.8 (mean 21.50, SD 0.97) participated in this study. An analogue pressure algometer was used for the evaluation of muscle tenderness of the following masticatory muscles: superficial and deep parts of the masseter muscle; anterior and posterior parts of the temporal muscle; and the tissues adjacent to the lateral and dorsal part of the temporomandibular joint capsule. Each patient described the algometry result for the individual components of the masticatory motor system, by selecting each time the intensity of pain on a 100 mm Visual Analogue Scale (VAS) ruler. The area under the receiver operating characteristic (ROC) curve, indicating the discriminatory efficiency for asymptomatic subjects and patients with temporomandibular dysfunction according to the dysfunction Di index, was the largest for the mean pain value (AUC = 0.8572; SEM = 0.0531). The 7.4 VAS cut-off point marked 95.3% specificity for this variable in identifying healthy subjects and 58.4% sensitivity in identifying patients with symptoms of dysfunctions (accuracy 68.1%). Assuming comparable sensitivity (74.9%) and specificity (74.2%) for a diagnostic test, there was test accuracy of 74.5% at the 4.2 VAS cut-off point.