Data collection procedures
TMD, bleeding, telescopic, pain
STERILE, BLEEDING, PAD, SECONDARY
Data were collected in a quiet room, whose access was restricted to researchers and study participants to ensure privacy.Anthropometric assessments were carried out by measuring participants’ body mass with a digital scale (OrionA Visual Analogue Scale (VAS) positioned horizontally was then shown to participants by a blinded evaluator, who asked them to mark their current level of pain on it. VAS is a validated (accurate) and reliable (reproducible) instrument to measure pain intensity for clinical and research purposes.Immediately after the VAS measurement, the oxygenation of the masseter muscles on both sides of patients’ face was measured by the same blinded examiner using Near-Infrared Spectroscopy (NIRS) (Portamon, ArtinisThen, the most sensitive trigger point of the masseter muscle was identified by palpation by the lead researcher, who marked its position on the skin with a white pencil and registered it on participants’ medical records.The lead researcher used drawing envelopes to randomize the therapeutic interventionDry needling was performed with a sterile acupuncture needle (0.20 × 13 mm, Qinzhou, China) inserted into the most sensitive trigger point identified in the masseter muscle. After insertion into the skin with the aid of a cursor, the needle was deepened into the muscle and moved 10 times outward and inward without leaving the skin. Its direction was changed to various locations in the area at an average rate of one movement per second. Right after needle removal, light pressure was applied with a cotton pad at the puncture site to prevent bleeding. Then, the NIRS measurement was repeated by the secondary evaluator, (blinded to the administered therapy), enabling the verification of any change in tissue oxygenation. VAS measurements were also repeated by the blinded evaluator.An acupuncture needle specifically adapted for this test was used in the sham procedure. A telescopic tube was fixed to a plastic base with 1 cm in diameter, which prevented the needle to penetrate the skin when manipulated, thus only simulating the sensation of the needle impact on the skin. This plastic base was immobile and fixed to the skin with a small piece of double-sided tape, being removed with a quick movement after one minute. Light pressure with a cotton pad was exerted on the site, as with the active DN procedure.In the second session, after seven days of washout, participants were instructed to neither seek any type of intervention or treatment for TMD nor take any analgesics or anti-inflammatory drugs for at least 24 hours.