Aims: To determine the temporomandibular joint (TMJ) pressure
pain threshold (PPT) in female patients with rheumatoid arthritis
(RA) and TMJ involvement in comparison with healthy females, in
order to determine its clinical usefulness for local pain assessment.
Methods: Forty-two female patients with the diagnosis of RA, 17
of them positive and 25 negative for rheumatoid factor were investigated,
as well as 17 healthy females. A pressure algometer was
used to assess the PPT over the TMJ and (as a reference) the center
of the glabella. The mean of the second and third TMJ PPT
was used in the analysis, and the ratio between the TMJ PPT and
the PPT of the reference site (PPT ratio) was calculated. Temporomandibular
joint resting pain and pain upon maximum voluntary
mouth opening was assessed by a visual analog scale on each side.
Results: The TMJ PPT (median/10th to 90th percentile) and PPT
ratio were significantly lower in the RA patients (148/64 to 220
and 0.63/0.40 to 1.01, respectively) than in the healthy individuals
(217/111 to 352 and 0.85/0.51 to 1.25), but the overlap was considerable.
Conclusion: This study shows that the PPT of the TMJ
in RA patients is lower than in healthy individuals and that it can
be used for pain assessment. However, the clinical use of the TMJ
PPT and PPT ratio measurements alone is limited from a diagnostic
point of view. J OROFAC PAIN 2003;17:326–332.