Does forward head posture correction improve temporomandibular joint dysfunction? A pilot randomized trial using a cervical extension traction orthotic

Context: This pilot study assessed participants adherence rate and the effect size needed to determine the sample size for a full-scale study evaluating the effectiveness of forward head posture (FHP) correction on temporomandibular disorders (TMDs) and symptoms. Moreover, the potential impact of adding FHP correction to a standard conservative protocol for treatment of TMD severity, pain, and pain-free mouth opening range is explored. Objectives: The primary objective was to investigate the additional effect of FHP correction by a cervical extension traction (CET) orthotic on myogenic TMD symptoms of pain and function. Methods: A total of 21 participants (19 females) were enrolled and completed the study. The participants’ mean age was 21.99±2.06 years, body mass index (BMI) 22.92±4.27 kg/m². A randomized clinical trial was conducted with participants who were randomly divided into two groups: 1) an experimental group with 10 participants receiving a FHP CET orthotic and a conservative TMD protocol; and 2) a control group with 11 participants receiving the conservative TMD protocol and a placebo CET device utilizing a standard pillow. Outcome assessments included: TMD severity with Fonseca’s questionnaire, numerical rating scale for pain intensity, maximum mouth opening (MMO), and the craniovertebral angle (CVA) to measure FHP. Assessments were performed at three time points (baseline, 3rd week, 6th week), and three treatment sessions per week for six consecutive weeks were administered. Results: Both groups achieved a high adherence rate to the study protocol (≥90 %). Within-group analysis for both groups, across the three time points, identified significant differences utilizing Friedman’s test (p<0.001) between measures for orofacial pain, TMD severity, MMO, and CVA. Between-group comparison identified no difference at the follow-up assessments for orofacial pain or MMO measures (p>0.05). The Mann-Whitney U test for between-group comparisons identified a statistically significant difference in CVA at week 3 (p=0.01) and at the 6th week (p<0.001) favoring the experimental group. For the TMD severity score, no difference was found at week 3 (p=0.11) but there was a significant difference between groups at week 6 (p=0.02) favoring the experimental group. Conclusions: These preliminary findings suggest that adding FHP correction through the application of a CET orthotic might offer short-term selected benefits for chronic TMD symptoms, which would need to be confirmed in a full-scale trial. High adherence rates were found with a moderate effect size that provided data indicating that at least 38 participants would be required for a full-scale study.