Masseteric muscle dehiscence is a well known adverse aesthetic risk of jaw angle or jawline implants. While it has no adverse functional effects on lower jaw opening or closure, it creates a contour defect over the jaw angle area. It can occur in variable amounts from a small amount of jaw angle skeletonization to a more significant oblique jaw angle exposure.
The anatomic correction of masseteric muscle dehiscence is to reposition the muscle back over the bone, or more commonly, the jaw angle portion of the implant. But this is not always effective and when done using a traditional approach places a scar below the jaw angle area in the neck.
An alternative approach is a camouflage one in which volume is added to fill in the contour defect. The use of injectable fillers or injected fat are viable options. But for a more permanent or assured volume retention a variety of grafts and implants can be used. Tissue grafts like allogeneic dermis (Alloderm) and various types of implanted materials can also be used. (ePTFE, ultra soft silicone)
But their placement requires a transcutaneous approach with a skin incision. A neck incision is not very appealing given its aesthetic tradeoff. A more direct approach is a small incision right over the back end of the jaw angle. In men this usually places the incision at the junction of the hair bearing and non-hair bearing skin. Through a 1 cm incisional length any graft or implant can be placed to cover the extent of the contour defect by initially making a subcutaneous pocket.
While effective the aesthetic question is how well does this scar heal. In my experience this transcutaneous jaw angle incision heals extremely well due to both its small size and its location. It is also a safe approach as the pathway of the marginal mandibular nerve runs below it.
Dr. Barry Eppley
Indianapolis, Indiana