Prophylactic Training for the Prevention of Trismus in Connection With Radiation Therapy - a Randomised Study
Summary of the study programme
During Radiation therapy to the mouth, throat or trachea can fibrosis often occur in the
chewing muscles round the jaw causing a development of trismus (a limited jaw mobility).
Trismus can cause pain, difficulty in eating, swallowing, speech and difficulty with general
mouth hygiene. Despite the fact that this condition has been documented in older literature,
there is limited research in the incidence of trismus. There is need of randomised studies
to investigate the prevention of trismus both under and during Radiation Therapy.
The specific aims of this study are to investigate the effectiveness of Prophylactic
training with a muscle warm-up programme and a mechanical device (TheraBite) to prevent
trismus during Radiation Therapy and one year after completed therapy. The study also aims
to investigate the incidence of radiotherapy-induced trismus in patients who receive
radiotherapy to the masseter, temporalis, pterygoid muscles. Finally the study investigates
whether trismus affects quality of life.
Sixty consecutive patients, from two different radiation clinics in Sweden, are randomised
into the two different groups using a computer programme.
1. Intervention group: Daily training with a programme for TheraBite that trains passive
movement, preceded by a warm-up programme. Mouth opening measurements are made once a
week during treatment at the end of radiotherapy,three, six and 12 months after
2. Control group: Receiving traditional radiation therapy with nursing care, measuring the
patients mouth opening once a week during treatment, at the end of radiation
therapy,three, six, and 12 months after treatment. The same training programme as group
one is offered to this group as soon as evidence of trismus develops.
This training is recorded by the patient in a log book. Weight, height, Mucositis analysis
and quality of life are made before the commencement of radiation therapy, at the end of
radiation therapy, three, six, and 12 months after treatment. The patient's weight is
measured every week.
The results of this study will give new and vital information that can give a basis to
develop a clinical method of identifying and treating cancer patients who suffer from
trismus. Thus giving new knowledge which can be used to formulate clinical practices.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Prevention
Change in Jaw mobility measurement during Radiotherapy
Proportion of participants free from trismus at the end of Radiotherapy.
Up to 7 weeks
Sussanne Börjeson, Med dr
Department of Medicine and Care, Division of Nursing Sciences, Faculty of Health Sciences, Linköping University, Sweden
Sweden: Regional Ethical Review Board