The objectives of this pilot study are to determine the effectiveness of a manual therapy (MT) protocol plus the use of a dynamic jaw opening device on the maximal interincisor distance; on trismus symptoms; on pain-disability outcomes and on the quality of life, anxiety, and depression in subjects with trismus. The proposed pilot study will comprise a single subject design with multiple baseline measures and during treatment phases to determine the effectiveness of the treatment protocol. A minimum sample of 10 subjects will be recruited. The Health Research Ethics Board of Alberta Cancer Committee will approve this study. Participants will receive a MT protocol plus exercises and the use of the DTS device for 6 months. The first two weeks of treatment will involve only MT and opening exercises.After this initial 2 weeks, the DTS will be introduced. The participants will receive a session of 30-45 minutes of MT three/two times per week, for 24 weeks. All participants will be instructed how to use the Dynasplint® Trismus System at home.