Deep dry needling of trigger points located in the lateral pterygoid muscle: Efficacy and safety of treatment for management of myofascial pain and temporomandibular dysfunction

BACKGROUND: To determine whether deep dry needling (DDN) of trigger points (TPs) in the lateral pterygoid muscle (LPM) would significantly reduce pain and improve function, compared with methocarbamol/paracetamol medication. MATERIAL AND METHODS: Forty-eight patients with chronic myofascial pain located in the LPM were selected and randomly assigned to one of two groups (DDN test group, n=24; drug-treated control group, n=24). The test group received three applications of needling of the LPM once per week for three weeks, while control group patients were given two tablets of a methocarbamol/paracetamol combination every six hours for three weeks. Assessments were carried out pretreatment, 2 and 8 weeks after finishing the treatment. RESULTS: A statistically significant difference (p<0.05) was detected for both groups with respect to pain reduction at rest and with mastication, but the DDN test group had significantly better levels of pain reduction. Moreover, statistically significant differences (p<0.05) up to day 70 in the test group were seen with respect to maximum mouth opening, laterality and protrusion movements compared with pretreatment values. Pain reduction in the test group was greater as a function of pain intensity at baseline. The evaluation of efficacy as assessed both by patients/investigators was better for the test group. 41% of the patients receiving the combination drug treatment described unpleasant side effects (mostly drowsiness). CONCLUSIONS: DDN of TPs in the LPM showed better efficacy in reducing pain and improving maximum mouth opening, laterality, and protrusion movements compared with methocarbamol/paracetamol treatment. No adverse events were observed with respect to DDN. Key words: Myofascial pain syndrome, myofascial trigger points, deep dry needling, lateral pterygoid muscle, randomized controlled trial, temporomandibular disorders.