Predictors for trismus in patients receiving radiotherapy

Abstract

Background: Trismus, a restricted mouth opening in head and neck cancer patients may be caused by tumor infiltration in masticatory muscles, radiation-induced fibrosis or scarring after surgery. It may impede oral functioning severely. The aims of our study were to determine: (1) the incidence of trismus at various time points; and (2) the patient, tumor, and treatment characteristics that predict the development of trismus after radiotherapy in head and neck cancer patients using a large database (n ¼ 641). Methods: Maximal mouth opening was measured prior to and 6, 12, 18, 24, 36, and 48 months after radiotherapy. Patient, tumor, and treatment characteristics were analyzed as potential predictors for trismus using a multivariable logistic regression analysis. Results: At six months after radiotherapy, 28.1% of the patients without trismus prior to radiotherapy developed trismus for the first time. At subsequent time points the incidence declined. Over a total period of 48 months after radiotherapy, the incidence of trismus was 3.6 per 10 person years at risk. Patients who had tumors located in the oral cavity, oropharynx or nasopharynx, and the salivary glands or ear, and who had a longer overall treatment time of radiotherapy, were more likely to develop trismus in the first six months after radiotherapy. Maximal mouth opening was a predictor for developing trismus at all time points. Conclusion: Incidence of trismus is 3.6 per 10 person years at risk. Tumor localization and overall treatment time of radiotherapy are predictors for developing trismus the first six months after radiotherapy. Maximal mouth opening is a significant predictor for developing trismus at all time points. Regular measurements of maximal mouth opening are needed to predict trismus.

Temporomandibular disorder in head and neck cancer patients undergoing radiotherapy: Clinical findings and patient‐reported symptoms

“…This is in line with other studies that have shown an incidence of trismus of approximately one-third of patients undergoing radiotherapy. 3,5,14 The masseter muscle has previously been identified as a critical risk structure for radiation-induced trismus in HNC, and undoubtedly, the clinical findings and patient-reported outcomes in this study support that theory. 15,16 Keeping in mind the high incidence of TMD symptoms prior to radiotherapy in this population, it can be assumed that the etiology of trismus is multifactorial and a result of both ionizing radiation and longstanding biting parafunction and overloading.…”

Trismus in patients with head and neck cancer and 5-year overall survival

“…In the present study, patients with oral cancer had significantly more severe trismus at 12-month follow-up, which indicates that this subgroup might benefit the most from mouth-opening exercises. It has previously been shown that both oropharyngeal cancer and oral cancer and its treatment predispose patients to trismus, which our study also indicates [5,15,16]. We therefore suggest that consideration should especially be given to patients with the greatest needs, i.e.…”

“…The incidence has been reported to be as high as 79% [1] while a number of studies indicate an incidence between 38% and 52% [2][3][4] where the majority of patients have received 3D conformal radiotherapy (3DCRT). Trismus severity seems to peak at 6 months after treatment and becomes somewhat lower at 12 months after treatment [3,5]. Newer treatment modalities, in particular intensity modulated radiotherapy (IMRT) are reported to have lower risk for trismus development [6,7].…”

Treatment of late sequelae after radiotherapy for head and neck cancer

“…The prevalence of trismus primarily depends on tumor site and size, being the highest in patients with tumors close to the mastication apparatus, i.e. parotid lesions, nasopharyngeal and lateralized oropharyngeal or posterior oral cavity primaries [162–164]. The wide prevalence range reported in the literature reflects the differences in the studied populations and, consequently, the dose burden across the studies.…”