Outcome of Treatment With Botulinum toxinA in Patients With Temporomandibular Myofascial Pain

June 19, 2026 updated by: Azhar Ahmed, PAEC General Hospital, Islamabad
Purpose: The aim of this study is to investigate the effectiveness and patient reported outcomes (interincisal distance and temporomandibular myofascial pain) of treatment with intramuscularly administered BTX-A vs N/S in patients with temporomandibular myofascial pain. OBJECTIVES: To determine the outcome of treatment with botulinum toxin-A vs N/S in patients with temporomandibular myofascial pain.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

OPERATIONAL DEFINITIONS:

Temporomandibular myofascial pain: Presence of any one or more of the following plus positives:

Pain in the Jaw Muscles: Persistent or recurrent pain located in the muscles of mastication (muscles that move the jaw).

Tenderness on Palpation: The pain is associated with tenderness that is identified during palpation of the affected muscles, particularly in the masseter, temporalis.

Limited Range of Motion: Patients often exhibit a reduced range of motion in the jaw.

OUTCOMES:

Temporomandibular myofascial pain score: Pain score will be assessed before and after 4, 8, and 12 weeks using visual analogue scale. It would determine subjective pain experience of patients. Visual Analogue Scale (VAS) represents continuous pain intensity, where the left end of the line indicates "no pain," while the right end denotes "worst pain imaginable." Patients indicates their level of pain (in cm), by marking a single point on the line.

Interincisal Distance: The interincisal distance refers to the measurement between the edges of the upper and lower central incisors when the jaw is fully opened using vernier caliper and it would be quantified in mm. Normal mouth opening ranges from 40-60 mm, mouth opening less than 40 mm would be consider as trismus.

HYPOTHESIS:

Botulinum toxin-A injection of 10-100 units would reduce the pain and increase the interincisal distance in patients with TMJ-MFP.

Study Type

Interventional

Enrollment (Actual)

118

Phase

  • Phase 4

Contacts and Locations

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

Study Locations

  • Pakistan
    • Islamabad
      • Islamabad, Islamabad, Pakistan, 44000
        • PAEC General Hospital, Islamabad

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients presenting with temporomandibular myofascial pain (VAS ≥ 6) for more than one month will be included.
  • Both genders.
  • Age 18-70 years

Exclusion Criteria:

  • Patient with history of allergic reactions with botulinum toxin-A.
  • Medically compromised patients. Current pregnancy.
  • Use of medication by the patients that could interfere with the effect of botulinum toxin-A (gentamycin, baclofen, atropine, revastigmine, verapamil, succinylcholine)
  • Neuromuscular disorders.

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: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Botulinum Toxin-A (BTX-A) Group
Intramuscular injection of Botulinum Toxin-A (BTX-A) would be used in this study to evaluate its outcome on pain reduction and improvement in interincisal mouth opening in patients with temporomandibular myofascial pain.
Drug: Botulinum Toxin-A (Botulax - letibotulinumtoxinA)
In this study, intramuscular injection of Botulinum Toxin-A (50-100 units) would be administered to the patient using a 1 mL insulin syringe with a 26G needle at a dilution of 10 U/mL in normal saline. Injections would be given at 5 sites: 3 in the masseter muscle and 2 in the temporalis muscle, based on the patient's side of complaint (unilateral or bilateral). Topical lidocaine 5% cream would be applied before injection. The injection aims to reduce jaw muscle pain and increase interincisal mouth opening, allowing patients to resume normal daily activities without delay.
Drug: Normal Saline
Intramuscular injection of normal saline (N/S) 1 mL would be administered at the same sites (masseter and temporalis muscles) as a placebo comparator. Normal saline injection would not be expected to significantly reduce pain intensity or increase interincisal mouth opening compared to BTX-A.
Placebo Comparator: Normal Saline (Placebo Injection)
Out of 118 patients, 59 patients would be given intramuscular injection of normal saline as a placebo.
Drug: Botulinum Toxin-A (Botulax - letibotulinumtoxinA)
In this study, intramuscular injection of Botulinum Toxin-A (50-100 units) would be administered to the patient using a 1 mL insulin syringe with a 26G needle at a dilution of 10 U/mL in normal saline. Injections would be given at 5 sites: 3 in the masseter muscle and 2 in the temporalis muscle, based on the patient's side of complaint (unilateral or bilateral). Topical lidocaine 5% cream would be applied before injection. The injection aims to reduce jaw muscle pain and increase interincisal mouth opening, allowing patients to resume normal daily activities without delay.
Drug: Normal Saline
Intramuscular injection of normal saline (N/S) 1 mL would be administered at the same sites (masseter and temporalis muscles) as a placebo comparator. Normal saline injection would not be expected to significantly reduce pain intensity or increase interincisal mouth opening compared to BTX-A.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Measurement of post-injection pain in patients diagnosed with Temporomandibular Myofascial Pain
Time Frame: From enrolment to 4, 8, and 12 weeks post-injection
Pain: Post-injection pain outcome when measured using Visual Analogue Scale (VAS) would determine the subjective pain experience of patients. VAS is a straight, 10 cm long horizontal line. VAS represents continuous pain intensity, where the left end of the line indicates "no pain," while the right end denotes "worst pain imaginable." Patients indicate their level of pain (in cm) by marking a single point on the line.
From enrolment to 4, 8, and 12 weeks post-injection
Measurement of Interincisal mouth opening in patients diagnosed with Temporomandibular Myofascial Pain.
Time Frame: From enrolment to 4, 8, and 12 weeks post-injection
Interincisal Distance: Reduced mouth opening would be quantified in millimeters by measuring interincisal distance at maximum mouth opening using a Vernier caliper. Normal mouth opening ranges from 40 to 60 mm. Mouth opening less than 40 mm is considered trismus.
From enrolment to 4, 8, and 12 weeks post-injection

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Demographic data (name, age, gender)
Time Frame: From enrolment to 12 weeks post-injection
Name, age, gender would be used to assess the effects of demographic data on post-injection outcomes in patients with temporomandibular myofascial pain.
From enrolment to 12 weeks post-injection
Tenderness on palpation of masseter and temporalis muscles
Time Frame: From enrolment to 4, 8, and 12 weeks post-injection
Pain elicited upon digital palpation of the masseter and temporalis muscles would be assessed before and after injection to evaluate the effect of BTX-A on local muscle tenderness.
From enrolment to 4, 8, and 12 weeks post-injection
Adverse reactions following intramuscular injection
Time Frame: From enrolment to 12 weeks post-injection
Any immediate or delayed adverse reactions following intramuscular injection of BTX-A or normal saline would be recorded and assessed to ensure patient safety.
From enrolment to 12 weeks post-injection

Collaborators and Investigators

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

Sponsor

PAEC General Hospital, Islamabad

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 (Actual)

January 2, 2026

Primary Completion (Actual)

April 1, 2026

Study Completion (Actual)

April 1, 2026

Study Registration Dates

First Submitted

June 19, 2026

First Submitted That Met QC Criteria

June 19, 2026

First Posted (Actual)

June 25, 2026

Study Record Updates

Last Update Posted (Actual)

June 25, 2026

Last Update Submitted That Met QC Criteria

June 19, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PGHI-IRB(DME)-RCD-06-058

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

As the hospital where this study is being conducted does allow to share any collected data with other researchers due to patient confidentiality.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

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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