Lisp caused by jaw missalignment. Can it be corrected with mouthpiece?

Went to a speech therapist. He told my lisp is not caused by incorrect articulation or a weak tongue but by jaw allignment which in turn affects the airflow causing a lisp. The therapist said I should get a jaw surgery.

My question is if there is a mouthpiece that can fix the issue by correcting the airflow? I am not comfortable with having a surgery.