The current commercial types of jaw angle implants available are of two types, lateral widening and vertical lengthening. In reality each type also have a bit of the other dimension as well. A widening jaw angle implant can provide a very modest lengthening effect and the vertical lengthening style always provides some width increase as well. But the dominant effect lies in their style description.
In selecting the proper jaw angle implant style for a patient, the key is whether a normal or high jaw angle location exists. Technically this is determined by whether a normal or increased mandibular plane angle exists which is primarily a.radiographic/cephalometric assessment .While x-rays may help in making that determination, a clinical exam is really the most critical. This is because the natural shape of the jaw angle in many Caucasians frequently bends inward. Thus a patient can appear to have a high jaw angle when, in reality, it has adequate vertical length and really lacks width as the inward bend makes it look ‘missing’.
Many men have a decent jaw angle length but lack width and the lateral widening style is a good choice for them.
In the high jaw angle patient an inadequate jaw angle length exists and the vertical lengthening style is a better implant choice.
In some cases no standard jaw angle implant style or size is adequate to meet the the patient’s aesthetic needs. Be aware of pre-existing jaw angle asymmetries from prior surgeries (e.g., sagittal split osteotomies) or natural development and desired aesthetic outcomes for which standard implants may have no chance to achieve a favorable outcome. This is where the use of custom designed jaw angle implants have a very useful role. They may be more costly up front but one revision from using failed standard implants will more than offset those costs.
Dr. Barry Eppley