Mouth-opening device as a treatment modality in trismus patients with head and neck cancer and oral submucous fibrosis: a prospective study

Objectives: This study investigated the clinical effectiveness of intervention with an open-mouth exercise device designed to facilitate maximal interincisal opening (MIO) and improve quality of life in patients with head and neck (H&N) cancer and oral submucous fibrosis (OSF). Materials and methods: Sixty patients with H&N cancer, OSF, and trismus (MIO < 35 mm) participated in the functional rehabilitation program. An open-mouth exercise device intervention group and conventional group, each consisting of 20 patients, underwent a 12-week training and exercising program and follow-up. For the control group, an additional 20 patients were randomly selected to match the demographic characteristics of the aforementioned two groups. Results: The patients’ MIO improvements in the aforementioned three groups were 14.0, 10.5, and 1.3 mm, respectively. Conclusion: Results of this study confirm the significant improvement in average mouth-opening range. In addition, according to patient feedback, significant improvements in health-related quality of life and reductions in trismus symptoms occurred in the open-mouth exercise device group. Clinical relevance: This newly designed open-mouth exercise device can facilitate trismus patients with H&N cancer and OSF and improve mouth-opening range and quality of life.