NCT07726511 · UConn Health
Effects of Hard Gum Chewing on Facial Soft Tissue Morphology
(GUM-3D)
What this study is about
This pilot clinical trial will evaluate whether intentional chewing of a standardized hard chewing gum for 4 weeks produces measurable changes in facial morphology in healthy adults. Twenty participants aged 20-40 years will undergo three-dimensional facial imaging (3dMD) at baseline (T0), after the 4-week chewing intervention (T1), and following a 4-5-week a break from previous treatment (T2).
View original scientific description
This pilot clinical trial will evaluate whether intentional chewing of a standardized hard chewing gum for 4 weeks produces measurable changes in facial morphology in healthy adults. Twenty participants aged 20-40 years will undergo three-dimensional facial imaging (3dMD) at baseline (T0), after the 4-week chewing intervention (T1), and following a 4-5-week washout period (T2). Changes in facial soft-tissue morphology will be assessed using three-dimensional surface analysis, including heatmaps, regional surface displacement, and morphometric measurements. Secondary outcomes include self-reported muscle fatigue, soreness, adherence, and temporomandibular disorder (TMD) symptoms.
Interventions
BEHAVIORAL
Hard Gum Chewing
Participants will chew a standardized hard chewing gum (Jawliner®, hard hardness level) every other day for 4 weeks. Each session will consist of two 8-minute chewing blocks following a standardized protocol with controlled chewing pace, progressive force application, and alternating chewing sides. Total chewing time per session will be approximately 16 minutes.
Primary outcome measures
Changes in Facial Morphology Assessed by 3dMD Stereophotogrammetry
Time frame: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)
Quantification of facial morphology changes using three-dimensional stereophotogrammetry, including regional surface distance maps (heatmaps), linear and angular measurements, and global and regional RMS deviation values.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Healthy, non-smoking adults.
- Age 20 to 40 years.
- Presence of a full dentition from central incisor to first molar in all four quadrants, excluding second molars.
- Stable occlusion with no ongoing orthodontic treatment or myofunctional therapy.
- Ability and willingness to comply with the prescribed hard-gum chewing regimen for 4 weeks and attend all study visits.
- Ability to provide written informed consent.
Exclusion criteria
- Age younger than 20 years or older than 40 years.
- Evident facial asymmetry from a frontal view.
- Signs or symptoms of temporomandibular disorders (TMD) according to the Diagnostic Criteria for TMD (DC/TMD).
- Less than the normal range of condylar motion during maximum opening and closing.
- Parafunctional habits such as bruxism with pain, clenching, or habitual gum chewing for more than 1 hour per day.
- History of major craniofacial trauma, orthognathic surgery, or congenital craniofacial anomalies.
- Ongoing orthodontic treatment or recent removal of fixed appliances (\<6 months).
- Significant malocclusion or missing teeth in the anterior or premolar-first molar region that may affect mastication.
- Systemic diseases or medications affecting muscle or bone metabolism.
- Previous use of botulinum toxin (Botox) within the last 6 months or anticipated use during the study period.
- Pregnancy or lactation.
- Allergy or intolerance to the chewing gum ingredients.
Where
- Farmington, Connecticut
Collaborators
Charles Burstone Foundation
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 24, 2026 · Source of record for eligibility and locations