Google OT supplies. There are safe chewing tube like thingsyou might try. I also used gum we walked to school and he chewed gum and spit it back into the wrapper when we got there and I threw it away. And then other short periods if time in the afternoon. Also an electric toothbrush was a good thing at this time. If he was chewing his shirt I sent him to brush his teeth and I think the vibration gave him the sensory stuff he needed. He did out grow it.

...reading is pleasure, not just something teachers make you do in school.~B. Cleary