What are these things my orthodontist put in my mouth? (Photos)

So I have braces and a pretty severe open bite. Today at my appointment after tightening my wires my ortho put these two blue things in the back of my mouth. She kind of explained what they were but I'm still kind of confused as to what they are and what they do. I think she said they have something to do with helping my bite come together but I'm not sure. The material is hard and I can clearly feel them when I bite down if that helps.

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