A Randomized Feasibility Trial to Evaluate Use of the Jaw Dynasplint to Prevent Trismus in Patients With Head and Neck Cancer Receiving Primary or Adjuvant Radiation-Based Therapy.

Objective: This study was designed to assess the feasibility of using the Jaw Dynasplint System as an adjunct to conventional stretching exercises as a preventative measure against trismus in patients undergoing radiotherapy.
Methods: Study participants (n = 40) were randomized using a permuted block design to conventional stretching or stretching plus use of the Jaw Dynasplint 3 times per day for 30 minutes. Patients were instructed to record maximum interincisal opening each day as well as logging use of the Jaw Dynasplint.
Results: At 6 months after initiation of the preventative regimen, 50% of patients in the Dynasplint arm and 75% in the conventional stretching arm remained on their assigned therapy. Trismus was diagnosed in 2 patients in the control arm and in 4 patients in the Dynasplint arm. Only 25% (95% confidence interval = 11.1, 46.9) of patients in the Dynasplint arm used the device as prescribed.
Conclusions: The addition of the Jaw Dynasplint decreased compliance compared with conventional stretching. It is unlikely that the prescribed regimen will prove efficacious as a preventative measure due to low compliance.