Palpation and pressure pain threshold: reliability and validity in patients with temporomandibular disorders

This study assessed the interexaminer reliability and validity of palpation (PA) and pressure pain threshold (PPT) of the temporomandibular joint (TMJ) and the masseter and temporalis muscles in patients with temporomandibular disorders (TMD) and asymptomatic controls. Eighty (80) subjects were distributed into two groups: Group 1 consisted of 40 TMD patients with muscular and joint pain selected by RDC/TMD Axis I; and Group 2 (control) with 40 asymptomatic individuals. Training and calibration of examiners was undertaken prior to testing. Mean reliability values were 0.64 and 0.78 (PPT), and 0.59 and 0.75 (PA), for patients and controls, respectively. Results showed statistically significant differences (p<0.001), for PA and PPT among TMD patients compared with the control. The results also showed acceptable specificity values (above 0.90), although sensitivity had low values. The tests had low diagnostic validity to discriminate between patients and controls, with low positive predictive values (PPV).