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FaceGUM-3DNCT07726511

Effects of Hard Gum Chewing on Facial Soft Tissue Morphology

A study testing Hard Gum Chewing in people with Face, run by UConn Health at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

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. Read more about this study

Who is it for?
Ages 20 to 40 years
Conditions the study is for
Face
What is being tested?
Hard Gum Chewing
Could I receive a placebo?
No, everyone receives an active treatment
How many people
20 participants
Where
1 siteUnited States
Study dates
3 Jun 2026to 30 Jun 2028
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 20 to 40 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • 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.

Who cannot join

  • 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.
Show all 12Show fewer
  • 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.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Flavio Uribe (Chair, Depto Orthodontics; UConn School of dental medic contact

860-679-3170

furibe@uchc.edu

Georgiana Defilio contact

(860) 679-2550

GEDEFILIO@uchc.edu

United States1 site, 1 recruiting
  • UConn Health

    Farmington, Connecticut, 06030

    Flavio Uribe

    Recruiting

Other trials in United States

About this study

Official title: The Effect of Intentional Hard Gum Chewing on Facial Morphology: a 3DMD-based Analysis x

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.

Read the detailed description

Facial morphology is influenced by multiple functional factors, including masticatory muscle activity. Although hard gum chewing has been promoted as a method to improve facial definition and jawline appearance, there is limited scientific evidence demonstrating whether intentional chewing can produce measurable changes in facial soft tissues.

The purpose of this prospective pilot clinical trial is to evaluate the effect of intentional hard gum chewing on facial morphology using three-dimensional stereophotogrammetry (3dMD). Twenty healthy adults aged 20-40 years will be enrolled. Participants will complete a standardized hard-gum chewing protocol every other day for 4 weeks. Each chewing session will last approximately 16 minutes and will follow a predefined protocol designed to provide a consistent masticatory stimulus.

Three-dimensional facial images will be obtained at baseline (T0), immediately after the intervention period (T1), and after a 4-5-week washout period (T2). Facial changes will be assessed through surface registration techniques, heatmap analysis, regional displacement measurements, and linear and angular soft-tissue measurements. Participants will also complete questionnaires regarding muscle fatigue, soreness, oral behaviors, and temporomandibular symptoms.

The primary objective is to determine whether intentional hard gum chewing produces measurable changes in facial morphology. Secondary objectives include evaluating participant-reported outcomes and monitoring for adverse events or symptoms suggestive of temporomandibular disorders.

Because this is a pilot study, the results will be used to estimate effect sizes and feasibility for future larger clinical trials investigating the relationship between masticatory activity and facial soft-tissue adaptation.

Conditions
Face
Being tested
Hard Gum Chewing
Keywords
Hard Gum Chewing, Facial Morphology, 3dMD, Stereophotogrammetry, Facial Soft Tissue, Heatmap Analysis, Chewing Gum, Masticatory Muscles, Three-Dimensional Imaging, Surface Distance Mapping
Medical subject headings
Facies

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Hard Gum ChewingBehavioural

    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.

Study groups in NCT07726511
Study groupRoleWhat they receive
Hard Gum Chewing InterventionExperimentalParticipants will perform a standardized hard-gum chewing protocol every other day for 4 weeks. Each session will last approximately 16 minutes and will follow a predefined chewing regimen. Three-dimensional facial images (3dMD) will be obtained at baseline (T0), immediately after the intervention period (T1), and after a 4-5-week washout period (T2) to evaluate changes in facial morphology.
Receives: Behavioral: Hard Gum Chewing

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Changes in Facial Morphology Assessed by 3dMD Stereophotogrammetry

    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.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

Secondary outcomes (13)
  1. Soft-Tissue Surface Topography Changes

    Evaluation of localized hypertonia and volumetric shifts using three-dimensional heatmap analysis and regional surface displacement measurements.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  2. Change in Body Weight

    Body weight will be measured in kilograms using a calibrated digital scale to monitor changes in body weight that could influence facial soft-tissue morphology.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  3. Body Height

    Standing height will be measured in centimeters using a Scale. Height will be used together with body weight to characterize participants' body size and, when applicable, to calculate body mass index.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  4. Participant-Reported Muscle Fatigue, Soreness, and Facial Definition Perception

    Self-reported outcomes related to muscle fatigue, soreness, chewing effort, and perceived facial definition collected through study questionnaires.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  5. Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Symptom Questionnaire

    Assessment of temporomandibular disorder symptoms using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Axis I Symptom Questionnaire. This questionnaire is part of the standardized DC/TMD diagnostic protocol and evaluates jaw pain, headache attributed to TMD, joint noises, jaw locking, and functional symptoms. Responses are recorded as presence or absence of symptoms and do not generate a total score. Presence/absence of symptoms (Yes/No). This questionnaire does not generate a total score.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  6. Oral Behaviors

    Assessment of oral parafunctional behaviors using the Oral Behaviors Checklist (OBC), one of the DC/TMD Axis II instruments. The questionnaire consists of 21 items assessing awake and sleep-related oral behaviors. A total score ranging from 0 to 84 will be calculated, with higher scores indicating more frequent oral parafunctional behaviors.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  7. Patient Health Questionnaire-4 (PHQ-4)

    Assessment of psychological distress using the Patient Health Questionnaire-4 (PHQ-4), included as part of the DC/TMD Axis II psychosocial assessment. Total scores range from 0 to 12, with higher scores indicating greater psychological distress.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  8. Jaw Functional Limitation Scale-8 (JFLS-8)

    Assessment of jaw functional limitation using the Jaw Functional Limitation Scale-8 (JFLS-8), a DC/TMD Axis II instrument. The questionnaire evaluates limitations in mastication, jaw mobility, and verbal and emotional expression. Scores range from 0 to 10, with higher scores indicating greater functional limitation.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  9. Patient Health Questionnaire-9 (PHQ-9)

    Assessment of depressive symptoms using the Patient Health Questionnaire-9 (PHQ-9), administered as part of the DC/TMD Axis II psychosocial evaluation. Total scores range from 0 to 27, with higher scores indicating greater depression severity.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  10. Jaw Functional Limitation Scale-20 (JFLS-20)

    Assessment of jaw functional limitation using the Jaw Functional Limitation Scale-20 (JFLS-20), a DC/TMD Axis II instrument. Scores range from 0 to 10, with higher scores indicating greater functional limitation.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  11. Generalized Anxiety Disorder-7 (GAD-7)

    Assessment of anxiety symptoms using the Generalized Anxiety Disorder-7 (GAD-7), administered as part of the DC/TMD Axis II psychosocial evaluation. Total scores range from 0 to 21, with higher scores indicating greater anxiety severity.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  12. Patient Health Questionnaire-15 (PHQ-15)

    Assessment of somatic symptom burden using the Patient Health Questionnaire-15 (PHQ-15), administered as part of the DC/TMD Axis II psychosocial evaluation. Total scores range from 0 to 30, with higher scores indicating greater somatic symptom severity.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

  13. Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Clinical Examination

    Clinical examination performed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Axis I Examination Protocol, including mandibular range of motion (mm), pain on palpation of the temporomandibular joints and masticatory muscles, pain during mandibular movements, joint sounds, and diagnostic clinical findings. Continuous variables will be reported in millimeters, and categorical findings will be reported as present or absent.

    Measured: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Jul 2026
  2. Study start3 Jun 2026
  3. Primary completion30 Jun 2028 (estimated)
  4. Study completion30 Jun 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
20 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07726511
Sponsor's protocol ID
26-191-1
Acronym
GUM-3D
Status last verified
Jul 2026
First submitted
13 Jul 2026
Last updated
24 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: De-identified individual participant data may be available upon reasonable request.

Publications

  • Tzakis MG, Kiliaridis S, Carlsson GE. Effect of a fatigue test and chewing training on masticatory muscles. J Oral Rehabil. 1994 Jan;21(1):33-45. doi: 10.1111/j.1365-2842.1994.tb01122.x.

    PubMed 8133387
  • Tzakis MG, Kiliaridis S, Carlsson GE. Effect of chewing training on masticatory efficiency. Acta Odontol Scand. 1989 Dec;47(6):355-60. doi: 10.3109/00016358909004803.

    PubMed 2609943
  • Kiliaridis S, Tzakis MG, Carlsson GE. Effects of fatigue and chewing training on maximal bite force and endurance. Am J Orthod Dentofacial Orthop. 1995 Apr;107(4):372-8. doi: 10.1016/s0889-5406(95)70089-7.

    PubMed 7709901
  • Shirai M, Kawai N, Hichijo N, Watanabe M, Mori H, Mitsui SN, Yasue A, Tanaka E. Effects of gum chewing exercise on maximum bite force according to facial morphology. Clin Exp Dent Res. 2018 Feb 22;4(2):48-51. doi: 10.1002/cre2.102. eCollection 2018 Apr.

    PubMed 29744215

Questions about this trial

What is this clinical trial studying?

A study testing Hard Gum Chewing in people with Face, run by UConn Health at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 24 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Flavio Uribe (Chair, Depto Orthodontics; UConn School of dental medic (860-679-3170, furibe@uchc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in Facial Morphology Assessed by 3dMD Stereophotogrammetry (time frame: Baseline (T0), Post-Intervention (T1, 4-5 weeks), and Washout (T2, 8-9 weeks)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07726511, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Jul 2026.

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