You might just be regarded. That's straight up standard English, "bone change" is the closest thing to slang in that sentence. Maxilla and mandible are the names of bones. Orthodontic retainer is the name of a piece of medical equipment, and upper arch is the proper medical term for a part of your mouth.

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\> I feel like my maxilla is too recessed instead of my mandible, and a part of that is the orthodontic retainer I’ve been wearing on my upper arch for 8 years. I’m 22 and 8 months. is it too late for bone change in the maxilla? I think I’m too mentally stable to understand any of these words.

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