Will mandibular angle implants help me? (photos)

Yes, you are correct in thinking that the properly chosen implant would produce a lower, more horizontally directed jawline, as well as improving the proportion between your lower and mid face.

Your insights into your facial proportions appear correct. You have a steep mandibular plane due to high jaw angles. Vertical lengthening jaw angle implants will drop down the angle and make the jawline appear more square than swooped. They can also add width so your cheeks from the front are not substantially wider than your jaw angles.