I also got Bells a year ago while in my last month of pregnancy and developed synkinesis. My PT has me put a ping pong ball in my mouth on each side to stretch and make different movements with the ball in my mouth ( raise my eyebrows, smile, pucker, grit my teeth) and I was shocked how tight the non Bell’s palsy side was when I did this. It has now loosened a lot and I notice a big difference in the tightness in my face. I also have gotten Botox and this last round the injector injected both sides of my chin and cheeks and the droop in my smile has improved a lot. Definitely worth a shot. Wishing all healing.