Effects of Hard Gum Chewing on Facial Soft Tissue Morphology

NCT07726511 | Recruiting

• 1 other identifier: 26-191-1
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Face

Keywords

Hard Gum Chewing; Facial Morphology; 3dMD; Stereophotogrammetry; Facial Soft Tissue; Heatmap Analysis; Chewing Gum; Masticatory Muscles; Three-Dimensional Imaging; Surface Distance Mapping

Outcome Measures

Primary Outcomes (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.

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

Secondary Outcomes (13)

• Soft-Tissue Surface Topography Changes

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

• Change in Body Weight

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

• Body Height

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

• Participant-Reported Muscle Fatigue, Soreness, and Facial Definition Perception

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

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

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

Study Arms (1)

Hard Gum Chewing Intervention

EXPERIMENTAL

Participants 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.

Behavioral: Hard Gum Chewing

Interventions

Hard Gum Chewing BEHAVIORAL

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.

Hard Gum Chewing Intervention

Eligibility Criteria

• Age: 20 Years - 40 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• UConn Health: lead
• Charles Burstone Foundation: collaborator

Study Sites (1)

UConn Health

Farmington, Connecticut, 06030, United States

RECRUITING

Related Publications (4)

• 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.

  PMID: 8133387 RESULT

• 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.

  PMID: 2609943 RESULT

• 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.

  PMID: 7709901 RESULT

• 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.

  PMID: 29744215 RESULT

MeSH Terms

Conditions

Facies

Condition Hierarchy (Ancestors)

Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Flavio Uribe

  UConn School of dental medicine

  PRINCIPAL INVESTIGATOR

• Thais Fernandes Poleti, PhD

  UConn School of dental medicine

  PRINCIPAL INVESTIGATOR

Central Study Contacts

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

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Chair, Orthodontics UConn School of Dental Medicine

Study Record Dates

• First Submitted: July 13, 2026
• First Posted: July 24, 2026
• Study Start: June 3, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): June 30, 2028
• Last Updated: July 24, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Beginning 6 months after publication and ending 5 years after publication.
• Access Criteria: De-identified data will be available upon reasonable request to the Principal Investigator.

Locations

US (1)