Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Contact information



Primary contact

Mr Colin Lunt


Contact details

Christie Hospital
550 Wilmslow Road
M20 4BX
United Kingdom
+44 161 446 3000

Additional identifiers

EudraCT number number


Protocol/serial number


Study information

Scientific title

Trismus RfPB trial: A randomised pilot study of TheraBite® use versus wooden spatula in the amelioration of trismus in head and neck cancer patients


Study hypothesis

Trismus is a tightening of jaw opening. The negative impact of trismus on the quality of life of head and neck cancer patients is well established. It affects eating, drinking, speaking and social function and is often as debilitating as any disfigurement resulting from treatment. The use of jaw exercises using a TheraBite® appliance following treatment has been shown to reduce the level of trismus in small studies. Many UK centres, however, use stacked wooden spatulas inserted between the incisors as a means of passive exercise. There is anecdotal evidence that suggests the use of exercises prior to treatment may help reduce the severity of the trismus experienced by the patient.

This study will enroll 112 head and neck cancer patients allocated by chance to use either the TheraBite® or wooden spatula, and patients will be asked to perform mouth exercises with either the Therabite or wooden spatula prior to and throughout their treatment. A review of the literature has suggested that use of passive mouth exercises could improve maximum mouth opening and hence QOL for these patients. Mouth opening will be the key outcome for the study measured over the time of treatments.

There is a need to evaluate both the effectiveness and cost-effectiveness of TheraBite® as opposed to wooden spatulas to evaluate whether they should be adopted as standard care in head and neck cancer patients. In this pilot trial, we will look at how well various questionnaires help us measure benefits of the TheraBite® to patients, as compared to usual care with wooden spatulas.

Ethics approval

NRES Committee North West - Greater Manchester North, First MREC approval date 01/06/2012, ref: 12/NW/0414

Study design

Randomised controlled study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Trismus in head and neck cancer patients


TheraBite® is intended for use in individuals who are restricted in their ability to open their jaws (trismus or jaw hypomobility)

Wooden spatula, Wooden lollipop shaped sticks

Follow Up Length: 6 month(s)

Intervention type



Not Applicable

Drug names

Primary outcome measure

Maximum mouth opening recorded daily

Secondary outcome measures

1. Patient compliance and tolerability measured at 3 and 6 months
2. Quality of Life and Health Economic outcome at baseline, 3 and 6 months

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Provision of signed, written informed consent
2. Aged 18 years and older
3. Able to read and write English sufficiently to be able to complete questionnaires
4. Stage 3/4 oral and oropharyngeal cancer patients undergoing primary chemoradiotherapy or surgical free flap
pluspost operative radiotherapy or post operative chemoradiotherapy
5. All patients will receive 60-70 Gy in 30-35 fractions over 6 to 7 weeks to the region of the pterygoid muscles
6. All patients will have at least some trismus as indicated by subjective tightening in the jaw

Participant type


Age group




Target number of participants

Planned Sample Size: 112; UK Sample Size: 112

Participant exclusion criteria

1. <12mm mouth opening (cannot use TheraBite®)
2. Anatomically unable to use Therabite for example patients who may only be partially dentate and to use the Therabite would place extreme stress on the existing teeth
3. Cognitive impairment as judged by the clinicians
4. International patients treated who will not have routine UK follow up
5. Previous surgery or radiotherapy (RT) to the head and neck prior to this diagnosis
6. Any patient who has no subjective tightening of the jaw

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Christie Hospital
550 Wilmslow Rd
M20 4BX
United Kingdom

Sponsor information


Christie Hospital NHS Foundation Trust (UK)

Sponsor details

550 Wilmslow Road
M20 4BX
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

NIHR (UK) - Central Commissioning Facility (CCF)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2018 protocol in: (added 10/04/2019)
2. 2019 results in: (added 10/04/2019)

Publication citations

Additional files

Editorial Notes

10/04/2019: Publication reference added. 13/01/2017: No publications found in PubMed, verifying study status with principal investigator.