Comparison of 26G and 30G Needles for Masseter Trigger Point Injections in Patients With Myofascial Pain Syndrome (MASS-NEEDLE)

November 3, 2026 updated by: Ceylan Guzel, Medipol University

Comparison of Two Needle Gauges (26G and 30G) for Masseter Muscle Trigger Point Injection in Myofascial Pain Syndrome: A Randomized Split-Face Controlled Trial

This randomized split-face study aims to compare the effects of 26G and 30G needles used for masseter trigger point injections with lidocaine in patients with myofascial pain syndrome. Both needle sizes are routinely used in clinical practice. Pain reduction from baseline to day 14 will be compared between the two sides of the face. Secondary outcomes include pain reduction at day 7, procedural pain, injection-site tenderness at 48 hours, bruising, and patient preference. The split-face design allows both needle sizes to be evaluated in the same patient, minimizing individual differences.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Both 26G and 30G needles were routinely used for masseter trigger point injection in our clinic. Comparing these gauges under otherwise standardized conditions may help clarify whether needle selection affects short-term pain reduction, procedural pain, and patient preference. A randomized split-face design permits this comparison within the same patient, reducing the influence of differences between individuals.

The primary objective of this study was to compare the within-patient reduction in palpation-evoked masseter pain between sides treated with 26G and 30G needles from baseline to day 14 following lidocaine injection. Secondary objectives were to compare pain reduction at day 7, overall procedural pain, injection-site tenderness at 48 hours, ecchymosis, and patient preference.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Adults aged 18-65 years.

Bilateral masseter myofascial pain persisting for at least 8 weeks.

Baseline palpation-evoked pain score of ≥6 on an 11-point Numerical Rating Scale (NRS) on each side.

Presence of at least one active myofascial trigger point within a palpable taut band in each masseter muscle, reproducing the patient's familiar pain.

Diagnosis established according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD).

No previous treatment for masseter myofascial pain.

Exclusion Criteria:

  • Concomitant temporomandibular joint arthralgia.

Known allergy to local anesthetics.

Pregnancy or lactation.

Active infection, open lesion, or malignancy at the injection site.

Bleeding diathesis or use of anticoagulant or antiplatelet medications.

Inability to cooperate with study procedures.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Bilateral Masseter Trigger Point Injection 26 G

All participants received bilateral masseter trigger point injections in a single session. A 26-gauge (26G) needle was randomly assigned to one masseter muscle and a 30-gauge (30G) needle to the contralateral masseter muscle using a computer-generated randomization sequence. Each masseter received 0.3 mL of 2% lidocaine without vasoconstrictor using a standardized injection technique. The right masseter was injected first in all participants. Participants and the outcome assessor were blinded to needle-gauge allocation, whereas the injecting clinician was not blinded.
Device: 26G Needle

A 26-gauge (0.45 × 13 mm) needle was used for masseter trigger point injection. A total of 0.3 mL of 2% lidocaine without vasoconstrictor was administered using a standardized injection technique.
Experimental: Bilateral Masseter Trigger Point Injection 30 G

All participants received bilateral masseter trigger point injections in a single session. A 26-gauge (26G) needle was randomly assigned to one masseter muscle and a 30-gauge (30G) needle to the contralateral masseter muscle using a computer-generated randomization sequence. Each masseter received 0.3 mL of 2% lidocaine without vasoconstrictor using a standardized injection technique. The right masseter was injected first in all participants. Participants and the outcome assessor were blinded to needle-gauge allocation, whereas the injecting clinician was not blinded.
Device: 30 Gauge Needle

A 30-gauge (0.45 × 13 mm) needle was used for masseter trigger point injection. A total of 0.3 mL of 2% lidocaine without vasoconstrictor was administered using a standardized injection technique.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Between-Needle Difference in Palpation-Evoked Masseter Pain Reduction From Baseline to Day 14
Time Frame: Baseline and Day 14 (14 days after injection)

Palpation-evoked masseter pain was assessed separately on each side using an 11-point Numerical Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst possible pain). At baseline and day 14, pain was recorded at the most painful trigger point identified during each assessment. Pain reduction was calculated as baseline NRS minus day 14 NRS for each side. The primary outcome was the within-participant difference in pain reduction between the 30G and 26G needle interventions (30G minus 26G). Positive values indicated greater pain reduction with 30G.
Baseline and Day 14 (14 days after injection)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Between-Needle Difference in Palpation-Evoked Masseter Pain Reduction at Day 7
Time Frame: Baseline and Day 7

Palpation-evoked masseter pain was assessed separately on each side using an 11-point Numerical Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst possible pain). Pain reduction was calculated as baseline NRS minus day 7 NRS for each side. The within-participant difference in pain reduction between the 30G and 26G needle interventions was calculated as 30G minus 26G. Positive values indicated greater pain reduction with 30G.
Baseline and Day 7

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Overall Procedural Pain During Masseter Trigger Point Injection
Time Frame: Day 0 (within 60 seconds after each injection)

Overall procedural pain was assessed separately for the 26G and 30G needle interventions using an 11-point Numerical Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst possible pain). Participants rated the entire injection procedure, including skin penetration, intramuscular needle manipulation, and lidocaine administration. Pain was recorded within 60 seconds after each injection. Within-participant pain scores were compared between needle gauges.
Day 0 (within 60 seconds after each injection)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Medipol University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

November 20, 2026

Primary Completion (Estimated)

January 1, 2027

Study Completion (Estimated)

February 1, 2027

Study Registration Dates

First Submitted

November 3, 2026

First Submitted That Met QC Criteria

November 3, 2026

First Posted (Actual)

November 9, 2026

Study Record Updates

Last Update Posted (Actual)

November 9, 2026

Last Update Submitted That Met QC Criteria

November 3, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • E-10840098-50.04-5377

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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