23 2 Introduction Oral cancer is currently in the top ten most common cancers worldwide.1 More insight into oral cancer and advancement in procedures have contributed to a more effective treatment. However, tumor eradication is not the only outcome that should be included in the evaluation of treatment success. Quality of life (QoL) of patients after cancer treatment has become more significant in the past decade.2 A patient’s self-reported Health Related QoL (HR-QoL) contributes to a better understanding of the range of health challenges patients with cancer may encounter.3 Those issues may continue long after initial curative treatment, and can be easily overlooked without adequate follow-up and assessment of HR-QoL. Primary curative treatment for oral cancer is mostly surgical ablation of the tumor, which can be followed by (chemo)radiotherapy, depending on affected regional lymph nodes (Nstage), extent of radical resection, and tumor specific growth factors.4,5 The sequelae of curative treatment can temporarily or permanently impair oral functions, because treatment may affect vital structures for mastication, such as dentition, musculature, and nerves.3,6 This is one of the considerations for the multidisciplinary team regarding cancer treatment.7,8 Masticatory performance depends on maximum bite force, tongue function, maximum mouth opening and dental status.9,10 Ideally, to prevent loss of masticatory function, early identification of a lesion and referral to a head and neck cancer (HNC) specialist for further examination is preferred. Early-stage oral cancers with a relatively small affected area are less likely to drastically impact oral function after treatment. However, treatment of advanced tumors will include a larger area and more likely involve multiple structures, thus having a higher risk of impacting speech, mastication and swallowing.11,12 Post-surgery deformities may occur, depending on resection procedure. Aesthetics can be (partially) restored by reconstructing the affected site. Unfortunately, reconstruction has its limitations. For example, soft tissue reconstruction following a glossectomy can replace the missing part of the tongue with a free flap such as the radial forearm flap.13 Although the result can be aesthetically acceptable, this is not necessarily equivalent to adequate oral function. Tongue function will mostly depend on the remaining tongue structures after resection.13,14 After segmental mandibulectomy, loss of vital structures is linked to the location and extent of the resection.11 Nonetheless, fibula reconstruction in combination with implant rehabilitation in larger resections can give adequate oral function, provided that there is no tongue impairment, resulting in less impact on masticatory functioning.15 In addition, (chemo)radiotherapy may be indicated during treatment with concomitant oral complications such as trismus, xerostomia, mucositis, dyspepsia and increased risk of infectious disease.16-18