Vertical Facial Morphology and Occlusal Force Changes After Masseter Botulinum Toxin Injection in Bruxism

June 23, 2026 updated by: Fatma Macit, Biruni University

Influence of Vertical Facial Morphology on Occlusal Force Changes After Masseter Botulinum Toxin Injection in Bruxism: A Prospective T-Scan Study

This study investigated whether the shape of the face affects how jaw muscles respond to botulinum toxin injections in people who grind their teeth (bruxism). Participants were divided into two groups based on their facial structure: low-angle (shorter face height) and normal-angle. Each participant received botulinum toxin type A injections into the masseter (jaw) muscle. Bite force measurements were taken before and 15 days after the injection using the T-Scan computerized occlusal analysis system. The study aimed to determine whether facial structure influences the early changes in bite force balance following the injection.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
34

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Locations

  • Turkey (Türkiye)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye), 34010
        • Department of Orthodontics, Faculty of Dentistry, Biruni University

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 18-40 years
  • Confirmed bruxism diagnosis through self-report and clinical signs
  • Full permanent dentition excluding third molars
  • Angle Class I molar relationship
  • No previous BTX-A injection within 6 months
  • GoGn/SN angle between 18° and 38° on lateral cephalometric radiograph

Exclusion Criteria:

  • Systemic neuromuscular disorders
  • Known allergy to botulinum toxin or its excipients
  • Pregnancy or breastfeeding
  • Active infection at the injection site
  • Concurrent use of medications known to interact with BTX-A
  • History of orthognathic surgery or prior temporomandibular joint surgery

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Masseter BTX-A Injection (Low-Angle and Normal-Angle Subgroups)
Patients with bruxism received bilateral masseter muscle injections of 25 units of botulinum toxin type A (Botox®, Allergan) per side. T-Scan occlusal force measurements were performed at baseline (T0) and day 15 post-injection (T1). Participants were stratified into low-angle and normal-angle subgroups based on GoGn/SN cephalometric angle.
Biological: Botulinum Toxin Type A (BOTOX) Injection
Botulinum toxin type A (Botox®, Allergan, Irvine, CA, USA) was injected bilaterally into the masseter muscle at a dose of 25 units per side (50 units total per patient). Injections were performed by a single experienced clinician under sterile conditions using a 30-gauge needle.
Other Names:
  • botox

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Center of Force (CoF)
Time Frame: Baseline (T0) and day 15 post-injection (T1)
The Center of Force (CoF) represents the geometric center of the total occlusal force distribution, measured using the T-Scan Novus™ computerized occlusal analysis system (version 10.0.40; Tekscan, Inc., South Boston, MA, USA). CoF values closer to zero indicate greater bilateral occlusal balance. Within-group changes (T0 to T1) and between-group differences were assessed and compared between low-angle (GoGn/SN < 26°) and normal-angle (GoGn/SN 26-38°) subgroups.
Baseline (T0) and day 15 post-injection (T1)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Anterior and Posterior Force Percentage
Time Frame: Baseline (T0) and day 15 post-injection (T1)
Anterior force percentage is defined as the combined occlusal force distribution of the anterior teeth, and posterior force percentage as the combined force distribution of the posterior teeth. Both were measured using the T-Scan Novus™ system at baseline (T0) and day 15 post-injection (T1). Within-group changes and between-group differences in anterior-posterior force distribution were evaluated and compared between low-angle and normal-angle subgroups.
Baseline (T0) and day 15 post-injection (T1)

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Biruni University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Esra Agaoğlu Mogul, Department of Orthodontics, Faculty of Dentistry, Biruni 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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 9, 2026

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 8, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 8, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 23, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 23, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 29, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 29, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 23, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • BiruniU-2026-09

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared due to patient privacy and ethical restrictions. Data are available from the corresponding author on reasonable request.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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