Intra- and interrater agreement of pressure pain threshold for masticatory structures in children reporting orofacial pain related to temporomandibular disorders and symptom-free children

AIMS: To determine intra- and interrater agreement of the pressure pain threshold (PPT) values for children reporting orofacial pain related to temporomadibular disorders and symptom-free subjects when the mean of 3 consecutive measurements or the mean of the last 2 consecutive measurements was considered. METHODS: Fourteen children reporting pain in masticatory muscles or the temporomandibular joint and 16 symptom-free children were selected at random from a sample of 100 children. Two trained raters used an algometer to obtain 3 consecutive measurements of PPT of the masticatory system sites. The children were evaluated in 3 sessions after a minimum period of 3 days after the initial evaluation. The intraclass correlation coefficient (ICC) was used to evaluate the levels of agreement. RESULTS: Excellent intra- and interrater agreement was observed (ICC > 0.75) for most of the structures evaluated in symptom-free children, and excellent and moderate agreement was obtained for the symptomatic group. Discarding the first of the 3 measurements increased the number of sites with ICC values classified as excellent in both groups. For evaluations performed on different days, this procedure reduced significantly the percentage of sites with ICC values classified as excellent only for the interrater agreement for the symptomatic group. CONCLUSION: The lower levels of reproducibility for the measurements obtained on different days in the children who reported pain may have been related to instability of their clinical signs and symptoms, and a PPT assessment based on the mean of 3 consecutive measurements or the procedure of discarding the first measure should be considered for such evaluations, especially when they are conducted by different raters. Algometry was shown to be a reliable tool for the evaluation of pain threshold in the masticatory structures of children.