11 1 the dose to the tumor can be maximized, while keeping the dose to the healthy tissues and organs at risk (OAR) acceptable.21 RT for HNC is usually divided into 35 fractions of 2 Gy spread out over seven weeks. Between each fraction, healthy tissue can recuperate from the radiation dose while malignant cells, who are less able to repair themselves, do not recover. However, damage to normal tissue cells still occurs, also caused by the reduced regenerative potential of irradiated tissue. Chemotherapy Chemotherapy is administered concomitantly with radiotherapy. Frequently used classical chemotherapeutics include cisplatin and carboplatin which are provided 3 times during the course of radiotherapy. Cisplatin acts by binding to DNA, thereby inhibiting the DNA synthesis. It enhances the effect of RT by inhibiting the repair of cells.22 Targeted therapy using the monoclonal antibody cetuximab is administered when patients are not fit enough to receive cisplatin. Cetuximab has fewer oral side effects, although systemic side effects such as acneiform rash, asthenia, and allergic reactions are common. Immunotherapy can be provided for patients with advanced head and neck cancer in a palliative setting, with immunotherapeutic agents such as nivolumab which can increase mean survival rates of patients.23 Toxicity after surgery During the oral phase of food processing, the teeth and tongue need to work together to transport the food to the molars. In addition, the muscles together with nerves and connective tissues need to break down the food to form a bolus, and transport the food backwards to the oropharyngeal surface of the tongue. Chewing and swallowing are interrelated, because chewing plays a fundamental role in the process of swallowing food.24 Surgical resection of the tongue will compromise lingual mobility and strength.3 Tongue dysfunction leads to impaired mastication, bolus formation and bolus transport, as tongue function is key to optimal mastication.3,25 Resection of masticatory and facial musculature will lead to facial deformity and loss of oral competence. A reduced closing pressure of the lips may lead to drooling.25 When nerves are transected, this may lead to sensory dysfunction of, e.g. the tongue, lips, chin, or facial musculature.26 Neck dissection can lead to impaired neck and shoulder mobility.27 Surgery may also result in alteration of the temporomandibular joint anatomy, disarticulation of the temporomandibular joint, loss and alteration of the masticatory muscles or loss of mandibular and maxillary structural integrity together with loss of teeth, leading to radical alteration of the oral anatomy.3 This can result in decreased tooth-to-tooth contact, sensory and soft-tissue deficits, and thus compromising the patients’ ability to form and manipulate a food bolus that is ready to be