How do I fix the mouth gap in a 3d scan to metahuman of a person smiling.

I made a metahuman from a 3D scan of a statue. The statue was of a person smiling and the person the statue was based on is dead, so there is no way to get a “Neutral Pose”. I did all the work as if the pose was neutral and all of it looks great except for the face that the mouth is stuck open. Any way i can fix it?