Why Do Asymmetries Occur After Jaw Angle Reduction Surgery?

Q: Dr. Eppley, I am interested in jaw angle reduction surgery but I am worried about the risk of asymmetries. In most before and after pictures that I have seen, I do notice asymmetries… one side of the jaw is thinner than the other. Why is that happening since X rays are being taken before surgery? Is it difficult to see where to shave during surgery? Is that a common risk? I also have seen some patients complaining about bumps and dips on the jawline (bony irregularities), why does that happen? Is that a common risk? Thank you so much.

A: As you have observed with excisional jaw angle reduction surgery, symmetry can be difficult to achieve. Having an x-ray before surgery is not helpful in executing the actual procedure. Doing the procedure inside the tight confines inside the mouth is quite different than making drawings on an x-ray. It may help estimate how much bone one wants to remove, but during surgery there is no way to see both sides simultaneously and no way to know if one side matches the other. In essence, excisional jaw angle reduction surgery is a guess on each side of the angle of the bone cut and how much bone is being removed. This problem can be magnified if the patient already has some existing asymmetry in the shape of the jaw angles. Converselly, burring or shaving the jaw angle is different. Because you are keeping the existing outline of the jaw angle bone and merely making it thinner, the risk of irregularities/asymmetries is dramatically reduced.

Dr. Barry Eppley

Indianapolis, Indiana