I think something similar happened when I started to wear a night guard to prevent bruxing when I started braces. It could be my imagination, however that my muscles shrank. My soft tissue envelope looks far thicker in my xrays. I had a consult with triaca and he said I would need Botox injections to shrink they muscles right after a chin wing and 6 months later because the muscles are enormous according to him and he thinks I stil clench very intensely at night.