My mouth doesn't open well.

There's a strong possibility of restricted mouth opening (trismus), so please don't force it open and come in as soon as possible. It often happens when the TMJ disc slips out of position and catches, or when the chewing muscles become tight. Normal mouth opening is about three finger widths, roughly 40mm — if you can't fit even two fingers, treatment is needed. Left untreated, it can progress to degenerative changes in the joint, and trying to force your mouth open on your own can worsen disc damage, so please avoid it.