Dynasplint Trismus System exercises for trismus secondary to head and neck cancer: a prospective explorative study

The Dynasplint Trismus System (DTS) can be used to treat trismus secondary to head and neck cancer. We conducted a prospective study with the following aims: (1) to determine the effects of DTS exercises on changes in mouth opening, pain, mandibular function, quality of life (QoL), and symptomatology and (2) to analyze the patients' perception on DTS exercises, including user satisfaction, experiences, comfort, and compliance.

The patients were instructed to exercise with the DTS for at least 16 weeks. Changes in mouth opening, pain, mandibular function, QoL, and symptomatology were evaluated, as well as the patients' perception of DTS exercises.

Eighteen consecutive patients were included. Baseline mouth opening was 22.6 mm (sd 7.6). After the patients completed the DTS exercise program, mouth opening increased (7.1 mm, sd 4.7) and perceived difficulty of opening the mouth improved significantly (p < 0.05). No significant effects were found in mandibular function, QoL, and overall symptomatology. The patients' perception was diverse. They reported effectiveness and positive feelings of the results and would recommend DTS exercises to other patients. About half of them thought DTS exercises were burdensome.

Mouth opening increased significantly after the DTS exercise program, relative to baseline. About one third of the gained increase was lost in the follow-up period. In general, the patients were satisfied about the effects and the DTS exercise program.