Effectiveness of cervical spine high- velocity, low-amplitude thrust added to behavioral education, soft tissue mobilization, and exercise for people with temporomandibular disorder with myalgia: A randomized clinical trial

OBJECTIVE: To determine the immediate and short-term effects of adding cervical spine high-velocity, low-amplitude thrust (HVLAT) to behavioral education, soft tissue mobilization, and a home exercise program on pain and dysfunction for people with a primary complaint of temporomandibular disorder (TMD) with myalgia. DESIGN: Randomized clinical trial. METHODS: Fifty individuals with TMD were randomly assigned to receive cervical HVLAT or sham manipulation for 4 visits over 4 weeks. Participants in both groups received other treatments, including standardized behavioral education, soft tissue mobilization, and a home exercise program. Primary outcomes included maximal mouth opening, the numeric pain-rating scale, the Jaw Functional Limitation Scale (JFLS), the Tampa Scale of Kinesiophobia for TMD (TSK-TMD), and a global rating of change (GROC). Self-report and objective measurements were taken at baseline, immediately after initial treatment, and follow-ups of 1 week and 4 weeks. A 2-by-4 mixed-model analysis of variance was used, with intervention group as the between-subjects factor and time as the within-subject factor. Separate analyses of variance were performed for dependent variables, and the hypothesis of interest was the group-bytime interaction. RESULTS: There was no significant interaction for maximal mouth opening, the numeric painrating scale, or secondary measures. There were significant 2-way interactions for the JFLS (d = 0.60) and TSK-TMD (d = 0.80). The HVLAT group had lower fear at 4 weeks and improved jaw function earlier (1 week). The GROC favored the HVLAT group, with significant differences in successful outcomes noted immediately after baseline treatment (thrust, 6/25; sham, 0/25) and at 4 weeks (thrust, 17/25; sham, 10/25). CONCLUSION: Both groups improved over time; however, differences between groups were small. There were significant differences between groups for the JFLS, TSK-TMD, and GROC. The additive clinical effect of cervical HVLAT to standard care remains unclear for treating TMD.