An interventional study of Trismus Device Prototype and Questionnaires in Trismus and Head and Neck Cancer, sponsored by University of California, San Francisco. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-13.
Sponsored by University of California, San Francisco · Not applicable, Interventional, and Supportive care
This trial evaluates how well a new therapeutic device works in managing trismus in patients who received radiation treatment for head and neck cancer. Radiation therapy is a common form of treatment in patients with head and neck cancers. However, changes to surrounding tissue following radiation therapy may lead to trismus, an inability to open the mouth fully. This can create significant functional impairment leading to malnutrition due to impaired chewing, risk of dental infections due to impaired oral hygiene, difficulty with speech, and decreased health-related quality of life. Exercise therapy is the mainstay of treatment for post-radiation trismus to help improve mobility and flexibility and increase range of mouth opening. This new device is non-invasive and is similar to other jaw stretching devices where a mouthpiece is placed between the teeth and a hand-lever is used to spread open the upper and lower jaw. However, it will also have additional sensors to measure pressure exerted by the hands and jaw as well as the distance to open the mouth which could help guide therapy. This study may help doctors customize a device to patient-specific needs, provide real-time feedback, and encourage compliance for trismus exercise therapy.
PRIMARY OBJECTIVE:
I. To assess the clinical efficacy of the trismus device, as measured by the change in maximum interincisal opening over the six-week treatment period.
SECONDARY OBJECTIVE:
I. To assess participants compliance rates and jaw opening pressures when using this device.
OUTLINE: Participants are assigned to 1 of 2 parts.
PART I: Participants test the trismus device and complete questionnaires on study.
PART II: Participants undergo exercise therapy with the trismus device under supervision of a speech language pathologist on study.
Participants will be on study for up to 6 weeks with a follow-up visit 7 days after completion.
107 studies on the registry are indexed under Trismus; 19 are open to participants now.
This study's enrollment of 35 is below the median of 52 across 99 interventional studies indexed under Trismus.
Browse Trismus studies →University of California, San Francisco is the lead sponsor of 2,169 studies on the registry; 372 are open to participants now.
Of its 267 completed or terminated interventional studies of FDA-regulated products, 202 (76%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Each participant will complete a single 45-minute visit in which consists of questionnaires about features that are important to them in trismus treatment, test a prototype of a trismus therapy device, and complete an online feedback questionnaire about their experience using the device.
Device: Trismus Device Prototype · Other: Questionnaires
Participants will be asked to use the device at least three times per week and up to daily for a period of 15-20 minutes over 6 weeks. Participants will be evaluated at baseline, at the 3-week (halfway) visit, and at the end of the 6-week treatment period under supervision of a speech language pathologist on study. Participants will then utilize a mobile app to help track treatment progress.
Device: Trismus Device Prototype · Other: Mobile Application
Device is noninvasive and will be inserted between patient's upper and lower teeth
Also known as: Medical Device
Surveys will be administered to participants
Also known as: Survey Administration
A study-specific, accompanying secure mobile application for users to track progress will be created.
Also known as: Mobile App
Mean change in maximum interincisal opening (MIO) over time
The mean change in MIO from baseline to end of treatment at 6 weeks will be reported
Time frame: Up to 6 weeks
Number of participants with device-related adverse events
During the study, research staff consisting of trained speech language pathologists will monitor patients undergoing exercise therapy for any adverse events. Adverse events for the eligible population will include the number of patients for whom the event occurred by the severity and relationship to study device. Adverse event rates will be coded by body system and Medical Dictionary for Regulatory Activities (MedDRA) classification term and graded using the CTCAE grading scale of (1) Mild to (5) Death.
Time frame: Up to 1 year
Rate of compliance
Percentage of participants who utilize the addition of the study-specific mobile application designed to track participant progress and participant compliance.
Time frame: Up to 1 year
Plan to share: No
No publications or documents are linked to this record.
Started Apr 2023 (actual). Primary completion is estimated for May 2027, 49 months after the start.
Of 57 non-industry interventional studies with no phase under Trismus, half reached primary completion within 8 months of starting (the median), counting those still running; a quarter within 4 and three quarters within 21. This study's planned 49 months is above that.
Counting every sponsor, half of 58 studies reached it within 8 months; a quarter within 4 and three quarters within 21.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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