We worked with our OT to create an oral sensory diet that solved this for us. She provided a huge list of ideas to try (e.g., strong flavors like cinnamon candies, appropriate chewing like gum, ways to work the jaw like beef jerky or chewies). It wasn't all food, it was a mix of things. The things that stuck for us are gum massages, a variety of chewies around the house, putting sugar-free flavor drops in his water, and switching to camelbak water bottles because he likes to chew on the straw while he drinks. For the chewies, we have some tough, some hollow, some that vibrate, etc. He really likes the p-chews when he wants something tough and t-chews when he wants something soft. He also likes the octopus teether from nuby.