Comparison of the effect of three types of oral appliance during experimental bruxism on the masseter muscle

Effect of different splint materials on biological responses - Effect of splint use on biological responses

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000059918

Enrollment

Registered

2025-11-28

Start date

2020-10-01

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bruxism

Interventions

Healthy adult participants perform experimental jaw-movement tasks in a laboratory setting. Under four oral appliance conditions (no appliance, hard-type appliance, soft-type appliance and combi-type

therefore, the study is registered as &quot

non-randomized&quot

in the UMIN system.

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Healthy adults Having at least 28 teeth No subjective or objective abnormalities in the oral cavity, temporomandibular joint, or craniocervical muscles No history of neurosurgical diseases

Exclusion criteria

Exclusion criteria: Taking medications that may affect psychological or cardiovascular systems Having signs or symptoms of temporomandibular disorders (TMD) in screening tests History of neurosurgical diseases Considered unsuitable for participation by the investigators

Design outcomes

Primary

Measure	Time frame
Change in tissue oxygen saturation (StO2) of the masseter muscles during experimental clenching and grinding tasks. StO2 is evaluated as the difference from the 4-min pre-task baseline mean to the minimum value and recovery course during the 30-s jaw movement and the subsequent 4-min recovery period, with comparisons between jaw-movement types (clenching vs. grinding) and oral appliance conditions (no appliance, hard, soft, and combi).	—

Measure

Time frame

Change in tissue oxygen saturation (StO2) of the masseter muscles during experimental clenching and grinding tasks. StO2 is evaluated as the difference from the 4-min pre-task baseline mean to the minimum value and recovery course during the 30-s jaw movement and the subsequent 4-min recovery period, with comparisons between jaw-movement types (clenching vs. grinding) and oral appliance conditions (no appliance, hard, soft, and combi).

—

Secondary

Measure	Time frame
Changes in other tissue oxygenation parameters of the masseter muscles (oxyhemoglobin, deoxyhemoglobin, total hemoglobin), defined as differences from the 4-min pre-task baseline mean during the 30-s task and the 4-min post-task recovery period. Masseter muscle activity assessed by surface electromyography (RMS and %MVC), comparing the pre-task baseline with the 30-s task period. Subjective fatigue levels evaluated using a visual analogue scale (VAS) immediately after each task. Subjective evaluations related to oral appliance use, including wearing comfort and perceived ease of clenching and grinding for each appliance condition, assessed by VAS after each task. Heart rate and heart rate variability indices (HR, CVRR, ccvHF, LF/HF), comparing the 4-min pre-task baseline with the 30-s task period and the 4-min post-task recovery period.	—

Measure

Time frame

Changes in other tissue oxygenation parameters of the masseter muscles (oxyhemoglobin, deoxyhemoglobin, total hemoglobin), defined as differences from the 4-min pre-task baseline mean during the 30-s task and the 4-min post-task recovery period. Masseter muscle activity assessed by surface electromyography (RMS and %MVC), comparing the pre-task baseline with the 30-s task period. Subjective fatigue levels evaluated using a visual analogue scale (VAS) immediately after each task. Subjective evaluations related to oral appliance use, including wearing comfort and perceived ease of clenching and grinding for each appliance condition, assessed by VAS after each task. Heart rate and heart rate variability indices (HR, CVRR, ccvHF, LF/HF), comparing the 4-min pre-task baseline with the 30-s task period and the 4-min post-task recovery period.

—

Countries

Japan

Contacts

Public ContactYuichiro Ohta

Tokyo Dental College Division of Special Needs Dentistry and Orofacial Pain, Department of Oral Health and Clinical Scien

ootayuuichirou@tdc.ac.jp03-5275-1582

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026