Comparison of Lidocaine, Mepivacaine, and Dry Needling in Myofascial Pain Syndrome

This study will be a randomized, controlled clinical trial designed to compare the effectiveness of dry needling, lidocaine, and mepivacaine injections in the treatment of myofascial pain in the masticatory muscles. Seventy-five participants with bilateral active myofascial trigger points in the masseter and/or temporalis muscles will be recruited. Participants will be randomly assigned to one of three intervention groups: dry needling, lidocaine (20 mg/mL), or mepivacaine (30 mg/mL).

Injections will be administered once a week for three consecutive weeks to both sides of the face. Pain levels will be evaluated using the Visual Analog Scale, depressive symptoms with the Beck Depression Inventory and temporomandibular disorder severity with the Fonseca Anamnestic Index. Measurements will be performed at baseline (prior to first injection) and one week after the third and final injection.

The study will be conducted at Istanbul Medipol University with ethics committee approval. Participants will be informed about the study procedures and informed consent will be obtained from all subjects. The primary objective of the study is to evaluate which intervention provides the most significant reduction in pain and associated symptoms of myofascial pain syndrome. Secondary outcomes will include improvements in depressive symptoms and temporomandibular disorder-related limitations.

• Dry Needling (Procedure): Dry needling applied to bilateral active trigger points in the masseter and temporalis muscles once per week for three weeks.
• Lidocaine Hydrochloride (Procedure): Lidocaine (20 mg/mL) injected into each active trigger point in the masseter and temporalis muscles once per week for three weeks.
• Mepivacaine Hydrochloride (Procedure): Mepivacaine (30 mg/mL) injected into each active trigger point in the masseter and temporalis muscles once per week for three weeks.

Primary outcomes

• Change in pain intensity based on the Visual Analog Scale [Baseline and one week after the third injection]: Pain intensity will be assessed using a 10 cm Visual Analog Scale (VAS), where 0 indicates no pain and 10 indicates the worst possible pain. The change in VAS scores from baseline to post-treatment will be analyzed.

Secondary outcomes

• Change in depressive symptoms based on the Beck Depression Inventory [Baseline and one week after the third injection]: Change in depressive symptoms based on the Beck Depression Inventory (BDI). The BDI is a 21-item self-reported questionnaire that measures depressive symptoms. Scores range from 0 to 63, with higher scores indicating more severe depression.
• Change in temporomandibular disorder severity based on the Fonseca Anamnestic Index [Baseline and one week after the third injection]: Change in temporomandibular disorder severity based on the Fonseca Anamnestic Index. The Fonseca Anamnestic Index consists of 10 items assessing TMD-related symptoms. Total scores range from 0 to 100, with higher scores indicating more severe temporomandibular dysfunction.

Sex: All, ages: 18 Years to 64 Years

Inclusion Criteria:

* Adults aged 18 to 64 years
* Presence of bilateral active myofascial trigger points in both the masseter and temporalis muscles
* Pain provoked by approximately 1 kg of external digital pressure on trigger points
* Willingness to participate and provide informed consent

Exclusion Criteria:

* Previous or ongoing treatment for temporomandibular disorders (e.g., occlusal splints, botulinum toxin injections)
* Presence of systemic neuromuscular disease
* Pregnancy or breastfeeding
* Use of analgesics, muscle relaxants, or antidepressants within the past 2 weeks
* Active infection, tumor, or trauma in the orofacial region

• Results publication: Munevveroglu S, Basegmez D, Karaca HB. Dry needling, lidocaine, and mepivacaine for myofascial pain and associated temporomandibular disorder and depressive symptoms: a randomized clinical trial. BMC Oral Health. 2026 Jun 22. doi: 10.1186/s12903-026-08986-0. Online ahead of print. PMID 42324523