Manual Therapy And Dynamic Splint Use For Trismus In Head And Neck Cancer Survivors

Abstract

Head and neck cancer (HNC) accounts for 3-5% of cancer cases in the United States. A known complication of oncological treatments for HNC is trismus, defined as limited mouth opening of less than 35mm. Trismus occurs in 6-86% of survivors. There is no standardized treatment for trismus, however, commonly used conservative interventions include manual therapy (MT), active exercises and assistive stretching devices. These interventions have shown promise as means to improve jaw mobility and alleviate symptoms. Without early detection and intervention, trismus is often chronic and progressive in nature. PURPOSE: To determine the feasibility of study processes, including recruitment rate, completion rate, adherence to protocol, and to establish processes for the dynamic splint mouthpiece fitting and intervention protocol. METHODS: A single subject design was used in this pilot feasibility study. Participants underwent a treatment protocol involving MT, exercises, and use of a dynamic splint at home for eight weeks. Multiple maximal interincisal opening (MIO) measures were performed at baseline testing, before and after each treatment session, and at the end of the intervention period. Researchers documented participant adherence to supervised sessions and dynamic splint use, and subjective responses to treatment after each session. RESULTS: 70% of participants had an improvement in their MIO after eight weeks, with an average increase of 3.0mm (range: -2.0 to 7.5mm). 90% of participants had 100% adherence to supervised sessions and 70% adherence to home use of the dynamic splint. Two participants were unable to be fitted with a dynamic splint mouthpiece due to insufficient mouth opening and, therefore used the flat plate of the device. Two participants required special adaptation of the mouthpiece, one due to dental pain and the other due to being edentulous. Treatment protocols required tailoring to facilitate comfort and adherence. CONCLUSION: Home use of a dynamic splint with MT shows promise as an intervention to address trismus in HNC survivors. The need for adaptations to the mouthpiece and treatment protocol should be anticipated, and a longer intervention period is recommended to optimize outcomes.Supported by: Faculty of Rehabilitation Medicine