The immediate effect of masseter trigger points compression on masticatory muscle activity

Masticatory muscle pain (MMP) is the most prevalent source of pain related to temporomandibular disorders. Some authors suggest that MMP may be related to the presence of myofascial trigger points (TrPs). Aim. The aim of the present study was to evaluate the immediate effect of masseter (MM) trigger point compressions technique on masticatory muscle activity and pressure pain thresholds (PPT). Material and methods. The participants were 15 healthy adults (10 women and 5 men; mean age 23.1±3.6). All participants included into the study had unilateral latent trigger points (TrPs) in the masseter muscle. Compression technique (CoT) of the latent TrPs in the masseter muscle was performed by pressing with index finger using constant, calibrated pressure of 2 kg/cm2 on the TrPs for 90 seconds. The electrical activity of the examined muscles and pressure pain thresholds for masseter muscles were recorded prior and after CoT. Results. Mean surface electrical activity of the MM muscle with TrPs and both sides of digastric muscle (DA) during resting mandibular position after CoT was significantly lower than before CoT (mean differences: MM 1=-0.783, p=0.001; DA 1=-0.312, p=0.01; DA 2=-0.229, p=0.025). Mean PPT of the MM muscles with TrPs after CoT was significantly higher comparing to baseline (1.819 vs.1.529 kg, respectively; p=0.001). Conclusions. CoT of the TrPs in masseter muscle reduces masticatory muscles resting activity. The use of CoT applied to the TrPs in masseter muscle increases pain pressure threshold. CoT may be effective in the management of MMP. (Ginszt M, Berger M, Gawda P, Bożyk A, Gawda J, Szkutnik J, Suwała M, Majcher P, Kapelan M. The immediate effect of masseter trigger points compression on masticatory muscle activity. Orthod Forum 2017; 13: 79-88).