The diagnostic value of pressure algometry in myofascial pain of the jaw muscles

Recent evidence suggests that evaluation of muscle tenderness in temporoman dibular disorders (TMDs) patients might be improved by the use of pressure algometry; nevertheless, the evaluation of the diagnostic value of this too l has received little attention. The aim of this study was to assess the di agnostic value of pressure algometry in myofascial pain of the jaw muscles, by calculation of sensitivity (Se), specificity (Sp) and positive predicti ve values (PPV). Pressure pain thresholds (PPTs) of masseter and anterior t emporalis muscles were assessed in 40 female myogenous TMD patients and 40 age-matched female controls. PPTs were significantly lower (P < 0.001) in T MD patients than in control subjects for both masseter and temporalis muscl es, being 40-50% of the control values. Setting a cutoff value 1 s.d. below the mean PPT values of control subject, sensitivity and specificity were 0 .67 and 0.85, respectively, for the masseter muscle and 0.77 and 0.87, resp ectively, for the temporalis muscle. When taking into account the prevalenc es of myofascial pain in the general population and in TMD clinics, the PPV ranged from 0.5 to 0.7. As a result of the low PPV, pressure algometry has strong limitations when used as a solitary diagnostic tool.