Objectives: The aim of this study was to evaluate brain activity in youth during chewing gum and wood stick using functional magnetic resonance imaging (fMRI). Methods: Two participants chewed wax gums and wood stick on the rhythm of 1 Hz during MRI scanning. The task paradigm was a block design and each chewing-rest procedure was repeated five times for 30s. Results: The brain regions activated during chewing gum and wood stick were the precentral gyrus, postcentral gyrus, supplementary motor area, thalamus cerebellum. The medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), hippocampus, and precuneus were additionally activated by mastication of the wood stick. Brain activation induced by chewing wood stick was higher than chewing gum. Conclusions: Our results suggest that mastication contribute to cognitive improvement through brain activity, this effect is stronger during chewing wood than gum. Therefore, eating harder foods may improve cognitive function more effectively.