Repeated Botulinum Toxin Type A Injections on Intramuscular Fat Accumulation in Individuals With Sleep Bruxism.

NCT07266064 | Completed

• 1 other identifier: Botox series
• Study Type: interventional
• Target: 27
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigates whether repeated botulinum toxin type A (BoNT-A) injections used to manage sleep bruxism lead to structural changes-specifically intramuscular fat accumulation-in the masseter muscle. Adults with probable sleep bruxism receive BoNT-A injections every six months and undergo ultrasound evaluations before each injection. By tracking fat percentage in the masseter muscle over multiple treatment cycles, the study aims to determine whether long-term BoNT-A use causes progressive structural alterations or remains safe for repeated clinical use.

Conditions

Bruxism; Bruxism, Sleep; Bruxism, Sleep-Related

Keywords

Botulinum Toxin Type A; Bruxism; Masseter Muscle; Ultrasonography; Adipose Tissue; Longitudinal Study

Outcome Measures

Primary Outcomes (1)

• Ultrasonographic imaging

  Cross-sectional imaging was obtained from the same anatomical plane. The probe position was determined at each visit using consistent anatomical landmarks-specifically the lower border of the mandibular corpus and the thickest region of the masseter muscle. The imaging plane part of the masseter, located between the posterior border adjacent to the parotid gland and the anterior border of the mandibular ramus. Ultrasonographic images were acquired both at rest (RST) and during maximum voluntary contraction (MVC) under identical device settings by the same experienced radiologist.

  From enrollment to 6 months

Study Arms (1)

BoNT-A

EXPERIMENTAL

At baseline, all participants underwent ultrasonographic evaluation of both masseter muscles (U0). Two weeks later, the first BoNT-A injection was administered bilaterally (U1). Thereafter, ultrasonography was repeated at six-month intervals (U1-U4). Each of the intermediate assessments was followed by a BoNT-A injection two weeks later (U2-U4), whereas the final assessment (U4) was not followed by injection. Thus, the protocol comprised five ultrasound sessions (U0-U4) and four BoNT-A sessions (U1-U4), unless the participant discontinued the study. All ultrasound examinations were performed by the same experienced examiner using the same device and standardized probe settings.

Other: Botilinum Toxin injection

Interventions

Botilinum Toxin injection OTHER

This prospective longitudinal interventional study included adults with probable sleep bruxism who received bilateral BoNT-A injections every six months, with ultrasonographic assessments also performed at six-month intervals, immediately before each new injection. The protocol therefore comprised four injection cycles and five ultrasound sessions. Ultrasonographic evaluations were conducted before the first injection and six months after each subsequent injection to quantify intramuscular fat percentage at rest and during maximum voluntary contraction. Fat area percentage was computed from standardized B-mode images using binary segmentation in CT-Analyzer software.

BoNT-A

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 18 years or older.
• Clinical diagnosis of probable sleep bruxism according to the international consensus criteria proposed by Lobbezoo et al.
• Indication for BoNT-A injection in the masseter muscle due to bruxism-related pain or muscle hypertrophy.
• Willingness to undergo repeated BoNT-A injections at six-month intervals.
• Willingness to participate in ultrasonographic evaluations at each follow-up visit.

You may not qualify if:

• Presence of neurological or neuromuscular disorders affecting the masticatory muscles (e.g., dystonia, myasthenia gravis).
• History of orofacial trauma, temporomandibular joint dysfunction, or maxillofacial surgery.
• Systemic diseases that may affect neuromuscular transmission or muscle metabolism.
• Use of medications known to interfere with neuromuscular function, including aminoglycoside antibiotics or corticosteroids.

Sponsors & Collaborators

• Melek Volkan Yazici: lead

Study Sites (1)

Ankara University, Faculty of Dentistry

Ankara, Cankaya, 06560, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Bruxism; Sleep Bruxism

Condition Hierarchy (Ancestors)

Tooth Diseases; Stomatognathic Diseases; Habits; Behavior; Parasomnias; Sleep Wake Disorders; Nervous System Diseases; Mental Disorders

Study Officials

• GOKHAN YAZICI, A/Prof

  Gazi University

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: The radiologist who acquired the ultrasonographic data and the researcher who performed the cross-sectional fat infiltration analysis were completely blinded to each other's procedures.
• Purpose: SCREENING
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Associate Professor

Model Details: Prospective, longitudinal study.

Study Record Dates

• First Submitted: November 22, 2025
• First Posted: December 5, 2025
• Study Start: January 2, 2024
• Primary Completion: November 20, 2025
• Study Completion: November 20, 2025
• Last Updated: December 5, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)