Very tight scars on bottom gums after jaw surgery. Can anything be done to regain flexibility? (Photo)

A year ago I had jaw surgery on the midline area (right above the chin) due to jaw fractures from an accident… since then I developed what the doctors say is scar tissue and it has been EXTREMELY TIGHT, I have limited range of motion in my mouth and I have a strong pulling sensation in that area and it affects other muscles in my face due to how tight the scared area is. I have difficulty eating due to this and my surgeons don’t know how to help… is there anything that can be done for this ?!!