In France, 11 316 new cases of upper aero-digestive tract cancer were estimated in 2012. These cancers are treated with a triple-therapy combining surgery, radiotherapy and chemotherapy/targeted therapies. Treatment-induced sequelae are often burdensome: reduction in mouth opening, eventually on to trismus, limitation of lips and tongue mobility, deterioration in oral hygiene, pain due to inflammation and muscle fibrosis. Trismus is defined as a mouth opening of less than 35mm in patients with head and neck cancers. It can be induced by treatments (surgery or radiotherapy) but is also reported at the time of diagnosis, due to the local evolution of the tumour.

Management of trismus and its consequences is currently mostly based on physiotherapy of maxillary constrictions in order to limit or decrease the reduction of mouth opening in these patients. Exercise protocols have been set up and evaluated in the literature, but with various results. The benefit of a physiotherapy intervention on trismus prevalence, mouth opening, and patients' quality of life has not yet been shown.

Our hypothesis is that at least 30% of patients treated with radiochemotherapy are affected by trismus. According to the nutrition national recommendations in oncology, patients the most at-risk of loco-regional complications are those who receive radiotherapy doses of 54Gy or more in the oropharynx and concomitant chemotherapy.

It is thus essential to provide these patients with an early and preventive management of trismus and its consequences, during the whole duration of the treatment.

The management of trismus and its side effects is essentially based on a re-education of maxillary constrictions to limit or reduce the loss of mouth opening in patients. Exercise protocols are in place and have been evaluated in the literature with discordant results. The beneficial effect of a rehabilitation program on the prevalence of trismus, oral opening and quality of life of patients is not yet clearly demonstrated.

Three studies did not show any significant beneficial effect of rehabilitation programs nor on the prevalence of trismus or the quality of life of patients. A 2014 randomized trial showed no benefit from a passive exercise program on trismus prevention and oral opening. Another 2011 study compared 374 patients, a control group and an intervention group following language mobility exercises, rehabilitation supervised by a physiotherapist and specific trismus prevention exercises with the help of a doctor. specific tool (Jaw Trainer) during and after radiotherapy. A third, more recent, randomized study evaluated the effect of a very comprehensive rehabilitation program consisting of a 45-minute session per week of rehabilitation with a physiotherapist, 7 exercises to be performed 5 times a day at home supplemented by chewing. chewing gum 5 times a day. These last two studies nonetheless concluded the importance of carrying out other work on the subject by working on the objectives of the studies, on the tools used, and on the implementation of the exercise program.

Also, an other study cited above does not show a significant difference in mouth opening between the two rehabilitation groups, but analyzes the adhesion and shows that it is significantly higher (59 versus 41 days) in the standard rehabilitation group, less burdensome for patients. Thus, the issue of patient adherence to active rehabilitation is real and essential to take into account in studies assessing the effect of a rehabilitation program on oral opening.

The prevalence of trismus as well as its management in physiotherapy and the effectiveness of a rehabilitation program are not clearly documented in France. Our hypothesis is that currently at least 30% of patients treated by radiochemotherapy are affected by a trismus. According to national oncology nutrition guidelines, the patients most at risk for locoregional complications are those who receive oropharyngeal ≥ 54 Gray radiotherapy doses, plus concomitant chemotherapy.

It seems essential to offer these patients early and preventive management of this symptom and its consequences, throughout the duration of treatment.

This study is all the more relevant as the progress of treatment of upper aero-digestive tract cancers have allowed an improvement in survival rates, with an increase in the number of patients living with sequelae related to treatments.

The major benefit for patients will be a decrease in the loss of mouth opening during and after treatment, with the consequent improvement of the criteria of well-being and quality of life: the resumption of a normal diet, a decrease the duration of artificial nutrition, better oral hygiene, improved speech and the recovery of mimicry. All this in order to accelerate the return to the most normal social and professional life possible.

Inclusion Criteria:

• Epidermoid carcinoma of the buccal cavity, oropharynx or type 1, 2 or 3 carcinoma of cavum according to the WHO classification.
• Radiotherapy (≥ 54Gy in the oropharynx) and concomitant chemotherapy (including targeted therapies) with or without surgery.
• Patients ≥ 18 years old, understanding French.
• Patients who gave their informed consent prior to the study

Exclusion Criteria:

• Disease and/or trauma with an effect on jaw mobility with permanent trismus.
• Psychiatric non-stabilized comorbidity.
• Lack of the median and lateral incisors.
• Metastatic patient.
• Legal inability or limited legal capacity.
• Medical or psychological conditions inducing incapacity of the subject to complete the study or give his/her consent.