Clinical model of factors influencing mandibular functioning. Within this study, a clinical model of factors influencing mandibular functioning was hypothesized and analyzed: (1) Tumor characteristics determine treatment modalities (extent of surgery, dose of radiotherapy, etc.). (2) Besides anti-tumor effects, treatments also induce adverse effects, resulting in oral symptoms. (3) These oral symptoms may result in restrictions in mandibular functioning. (4, 5) However, it is possible that some tumor characteristics or treatment characteristics influence mandibular functioning directly without actually resulting in specific oral symptoms. (6) Finally, tumor characteristics may induce oral symptoms directly