Relationship of calcitonin gene-related peptide in synovial tissues and temporomandibular joint pain in humans.

OBJECTIVE

To elucidate the expression of calcitonin gene-related peptide (CGRP) in synovial tissue taken from the human temporomandibular joint (TMJ) with internal derangement, and discuss the relationship between CGRP and joint pain.

STUDY

DESIGN

Using an immunohistochemical technique, 48 joints in 48 patients were examined. As controls, synovial tissue specimens from 7 joints with habitual dislocation without pain were also examined.

RESULTS

In all of the internal derangement and control subjects, CGRP-positive cells were observed in the connective tissues around the blood vessels beneath the lining cells. The extent score of CGRP was significantly higher in the internal derangement group than in the control group (P=.033). There was a significant positive correlation between the extent score of CGRP and joint pain (P=.036, r=0.30).

CONCLUSIONS

These results suggest that the expression of CGRP is increased in the synovial tissues from patients with internal derangement, and that CGRP seems to play an important role in the mechanism of pain production in patients with symptomatic internal derangement.