Centro Ricerche Cliniche Di Verona S.r.l.
Verona, Italy
Not recruiting
Study on Botulinum Toxin Type A for Reducing Jaw Muscle Size in Adults with Prominent Masseter Muscle
Verified siteRegistered drug
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What is this trial about?
A plain-language summary of the goals, design and what participants do
This clinical trial is focused on studying the effects of BOTOX (Botulinum Toxin Type A) on reducing the prominence of the masseter muscle in adults. The masseter muscle is one of the muscles in the jaw that can become enlarged, leading to a more prominent jawline. The study will compare the effectiveness and safety of BOTOX injections with a placebo in treating this condition.
The purpose of the study is to assess whether BOTOX can effectively reduce the size of the masseter muscle, thereby altering the appearance of the jawline. Participants in the study will receive either BOTOX or a placebo through injections into the muscle. The study will be conducted over a period of time, with regular assessments to monitor changes in the muscle's size and the overall appearance of the lower face.
Throughout the study, participants will be evaluated to determine any improvements in the prominence of the masseter muscle. These evaluations will include both the investigator's and the participant's assessments of changes in the muscle's size. The study aims to provide valuable information on the potential benefits of BOTOX for individuals with prominent masseter muscles.
The research process
The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.
Who can join the trial?
5 criteria
- Participants must have a Body Mass Index (BMI) calculated using the formula: weight in kilograms divided by height in meters squared (BMI = weight (kg)/height (m)2), rounded to the nearest whole number.
- Participants must have bilateral masseter muscle prominence (MMP), meaning the muscle prominence is the same on both the left and right sides of the face. This will be checked by the investigator during the screening and on the first day of the study.
- Participants must also agree that their masseter muscle prominence (MMP) is the same on both sides of the face on the first day of the study.
- Participants must be within the age range of 18 to 65 years old.
- Both male and female participants are eligible to join the study.
Who cannot join the trial?
9 criteria
- Patients with any other significant medical condition that might interfere with the study.
- Patients who are pregnant or breastfeeding.
- Patients who have had any surgery on the face or jaw in the past 6 months.
- Patients who have received any treatment with **BOTOX** or similar products in the past 6 months.
- Patients with a known allergy to **BOTOX** or any of its ingredients.
- Patients with a history of muscle or nerve disorders.
- Patients who are currently participating in another clinical trial.
- Patients who have a history of drug or alcohol abuse.
- Patients who are unable to comply with the study procedures.
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Verified sites
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Verified Verified Universita' Campus Bio-medico Di Roma
Rome, ItalyVerified Vrije Universiteit Brussel
Jette, Belgium
Trial locations
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Investigated drugs
BOTOX is a medication that contains a substance called botulinum toxin type A. It is used in this clinical trial to help reduce the size and prominence of the masseter muscles, which are the muscles located at the sides of your jaw. These muscles can sometimes become enlarged, leading to a more prominent jawline. BOTOX works by temporarily relaxing these muscles, which can help make the jawline appear slimmer and less pronounced. This trial is designed to test how effective and safe BOTOX is for people who have noticeable masseter muscle prominence.
What is already known about the treatment
BOTOX – BOTOX is administered through injections directly into the masseter muscle, which is located in the jaw area. It is currently being studied in clinical trials for its effectiveness in reducing the prominence of this muscle. The main therapeutic indication for BOTOX in this trial is to address masseter muscle prominence, which can affect facial aesthetics. At the molecular level, BOTOX works by blocking nerve signals to the muscles, leading to temporary muscle relaxation. It is classified pharmacologically as a neurotoxin, specifically botulinum toxin type A.
Investigated diseases
Masseter Muscle Prominence – Masseter Muscle Prominence is a condition characterized by the enlargement or hypertrophy of the masseter muscles, which are located at the angle of the jaw. This condition can lead to a more square-shaped jawline and may be associated with functional issues such as bruxism or teeth grinding. The progression of masseter muscle prominence can vary, with some individuals experiencing gradual enlargement over time. Factors such as genetics, habitual behaviors, and certain medical conditions can influence the development and progression of this condition. It is often more noticeable in individuals who frequently clench or grind their teeth. The prominence of the masseter muscle can affect facial aesthetics and may lead to concerns about facial symmetry.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-500568-37-00Protocol codeM23-123Estimated enrolment248 patientsSponsorAbbVie Deutschland GmbH & Co. KG
sourced from the EU Clinical Trials Register and site verification
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