A preliminary report on the efficacy of a dynamic jaw opening device (dynasplint trismus system) as part of the multimodal treatment of trismus in patients with head and neck cancer

Arch Phys Med Rehabil. 2010 Aug;91(8):1278-82. doi: 10.1016/j.apmr.2010.05.010.


Objective: To examine the effectiveness of a dynamic jaw opening device as part of a multimodal treatment strategy for trismus in patients with head and neck cancer.

Design: Retrospective cohort study.

Setting: Tertiary care cancer center.

Participants: Patients with head and neck cancer and trismus (N=20).

Intervention: All patients underwent assessment by a board-certified physiatrist and were referred to physical therapy for delivery of the DTS and instructed to progress use of the DTS to 30 minutes 3 times a day. Additional modalities for the treatment of trismus including pain medications and botulinum toxin injections were prescribed as clinically indicated.

Main outcome measures: Change in maximal interincisal distance (MID) as documented in the medical record.

Results: The use of the DTS as part of multimodal therapy including physical therapy, pain medications, and botulinum toxin injections as deemed clinically appropriate resulted in an overall improvement of the MID from 16.5mm to 23.5mm (P<.001). Patients who could comply with the treatment recommendations for DTS treatment did better than those who could not, with an improvement of the MID from 16 mm to 27 mm (P<.001) versus 17 mm to 22 mm (P=.88).

Conclusions: The DTS is a safe and effective component of a multimodal strategy for improving trismus associated with head and neck cancer and its treatment. Further investigation is needed to determine the relative efficacy of the treatment modalities available for trismus including physical therapy and other jaw stretching devices.

MeSH terms

  • Acute Disease
  • Adult
  • Aged
  • Analgesics / therapeutic use
  • Botulinum Toxins / therapeutic use
  • Chronic Disease
  • Cohort Studies
  • Combined Modality Therapy
  • Female
  • Head and Neck Neoplasms / complications*
  • Head and Neck Neoplasms / physiopathology
  • Humans
  • Male
  • Middle Aged
  • Physical Therapy Modalities
  • Retrospective Studies
  • Splints*
  • Trismus / etiology
  • Trismus / physiopathology
  • Trismus / rehabilitation*


  • Analgesics
  • Botulinum Toxins