To investigate the effects of deep dry needling (DN) of myofascial trigger points (MTrPs) of the masseter and temporalis on pain, pressure pain threshold (PPT), pain-free maximal jaw opening and temporomandibular disorder (TMD)-related disability in patients with sleep bruxism (SB) and myofascial TMD. Seventeen subjects (11 women, 6 men) aged 39±13 years (range 23-66) diagnosed with SB and myofascial TMD were invited to participate in this prospective case series study. Each subject received a deep DN intervention in the masseter and temporalis MTrPs. Pain intensity, PPT, pain-free maximal jaw opening and TMD-related disability were assessed before treatment, immediately after treatment and at 1-week follow-up. Jaw disability was assessed using the jaw disability checklist (JDC) at baseline and 1 week post-treatment only. One-way analyses of variance showed significant improvements in pain intensity, PPT and jaw opening (p<0.001). Post-hoc analysis revealed significant differences between baseline and post-intervention follow-up time points in pain (immediate: Cohen's d=1.72, p<0.001; 1 week: d=3.24, p<0.001), jaw opening (immediate: d=0.77, p<0.001; 1 week: d=1.02, p<0.001) and PPT in the masseter (immediate: d=1.02, p<0.001; 1 week: d=1.64, p<0.001) and temporalis (immediate: d=0.91, p=0.006; 1 week: d=1.8, p<0.001). A dependent t-test showed a significant improvement in jaw functioning, reflected by a large reduction in 1-week JDC scores relative to baseline (d=3.15, p<0.001).
Deep DN of active MTrPs in the masseter and temporalis in patients with myofascial TMD and SB was associated with immediate and 1-week improvements in pain, sensitivity, jaw opening and TMD-related disability.