A Scoping Review of Physiotherapeutic Interventions for Trismus in Head and Neck Cancer: Where Is the Manual Therapy?

, or restricted mouth opening, is a common side effect of treatment for head and neck cancer. This scoping review examined the characteristics, extent, and nature of existing research on manual therapy and jaw-mobilizing devices to prevent and manage trismus related to head and neck cancer. Six electronic databases were searched using the terms , and and the associated MeSH terms. The review focused on the factors related to intervention delivery: timing, adherence, completion rates, and adverse events. Nine studies were included. Eight examined the use of a jaw-mobilizing device, and one explored the benefit of remote telephone support. Two studies involved cancer survivors at risk of trismus, five involved survivors with trismus, and two included survivors both with and at risk of trismus. No studies were found examining physiotherapist provision of manual therapy. Within-group comparisons supported the benefit of using a jaw-mobilizing device to manage trismus, whereas significant between-groups differences were found only in non-randomized controlled trials. Survivor symptoms and intervention burden were reported reasons for poor adherence and completion rates. No benefit was found for the use of jaw-mobilizing devices for the prevention of trismus. Given the potential of manual therapy to enhance outcomes, physical therapist-led research is warranted.