A custom jawline implant is the most powerful changer of the shape of the lower face. Because it creates a volumetric expansion of the entire bony surface of the lower jaw that is responsible for its external appearance, it can create jawline changes that are not capable from any other operation. Even a sagittal split osteotomy can not replicate the 3D jawline changes that a custom imply can.
Custom jawline implants come in all sizes and shapes baed on the aesthetic needs of the patient. When possible it is ideal to have it placed in a front to back technique keeping it as a single one-piece implant. But hen the size of the jaw angle portion of the implant becomes greater than 7mms in width or its vertical height due to lengthening exceeds 40mms it is incapable of being safely placed in a front to back technique because of the risk of permanent injury to the mental nerve in the connecting subperiosteal tunnel between the larger chin and jaw angle pockets.
With custom jawline implants with these larger dimensions it is recessary ti split the implant into two calfs (midline split) and introduce it in a back to front technique. This has less potential for injury to they mental never because half of the chin is always smaller than a whole jaw angle.
While the midline split of the implant can be done in a straight line vertical fashion, I have evolved into make a more geometric midline split. This non-straight line cut allows for a more assured precise realignment of the implant that has less risk of any rotation changes in the implant as it heads back to the angles. This is most useful and of increased relevance in chins that have greater thickness to them.
This puzzle piece-like interface between the two halfs of the implant increases their surface area of contact and provides a more rigid re-estabishment of connection. When combined with permanent suture and screw fixation it is assured that the implant once again becomes as stable as it was before it was separated.
Dr. Barry Eppley
Indianapolis, Indiana